Moving 2.x branches

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@835134 13f79535-47bb-0310-9956-ffa450edef68

13 files changed, 3934 insertions, 0 deletions

diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/BaseAssemblyProcessor.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/BaseAssemblyProcessor.java
new file mode 100644
index 0000000000..03a087a5ec
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/BaseAssemblyProcessor.java
@@ -0,0 +1,906 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import static javax.xml.XMLConstants.W3C_XML_SCHEMA_INSTANCE_NS_URI;
+import static javax.xml.XMLConstants.XMLNS_ATTRIBUTE_NS_URI;
+import static javax.xml.stream.XMLStreamConstants.CDATA;
+import static javax.xml.stream.XMLStreamConstants.CHARACTERS;
+import static javax.xml.stream.XMLStreamConstants.COMMENT;
+import static javax.xml.stream.XMLStreamConstants.END_ELEMENT;
+import static javax.xml.stream.XMLStreamConstants.START_ELEMENT;
+import static org.apache.tuscany.sca.assembly.xml.Constants.ELEMENT;
+import static org.apache.tuscany.sca.assembly.xml.Constants.MANY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.MULTIPLICITY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.MUST_SUPPLY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.NAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.ONE_N;
+import static org.apache.tuscany.sca.assembly.xml.Constants.ONE_ONE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.PROPERTY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.PROPERTY_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.SCA11_NS;
+import static org.apache.tuscany.sca.assembly.xml.Constants.TARGET;
+import static org.apache.tuscany.sca.assembly.xml.Constants.TYPE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.VALUE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.VALUE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.ZERO_N;
+import static org.apache.tuscany.sca.assembly.xml.Constants.ZERO_ONE;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.StringTokenizer;
+
+import javax.xml.namespace.QName;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamConstants;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+import javax.xml.transform.dom.DOMSource;
+
+import org.apache.tuscany.sca.assembly.AbstractContract;
+import org.apache.tuscany.sca.assembly.AbstractProperty;
+import org.apache.tuscany.sca.assembly.AbstractReference;
+import org.apache.tuscany.sca.assembly.AssemblyFactory;
+import org.apache.tuscany.sca.assembly.Base;
+import org.apache.tuscany.sca.assembly.Binding;
+import org.apache.tuscany.sca.assembly.Component;
+import org.apache.tuscany.sca.assembly.ComponentService;
+import org.apache.tuscany.sca.assembly.ComponentType;
+import org.apache.tuscany.sca.assembly.Composite;
+import org.apache.tuscany.sca.assembly.ConstrainingType;
+import org.apache.tuscany.sca.assembly.Contract;
+import org.apache.tuscany.sca.assembly.Extensible;
+import org.apache.tuscany.sca.assembly.Extension;
+import org.apache.tuscany.sca.assembly.Implementation;
+import org.apache.tuscany.sca.assembly.Multiplicity;
+import org.apache.tuscany.sca.assembly.Reference;
+import org.apache.tuscany.sca.assembly.Service;
+import org.apache.tuscany.sca.contribution.processor.BaseStAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
+import org.apache.tuscany.sca.contribution.processor.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.processor.ContributionWriteException;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.StAXAttributeProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.interfacedef.InterfaceContract;
+import org.apache.tuscany.sca.monitor.Monitor;
+import org.apache.tuscany.sca.monitor.Problem;
+import org.apache.tuscany.sca.monitor.Problem.Severity;
+import org.apache.tuscany.sca.policy.Intent;
+import org.apache.tuscany.sca.policy.PolicyFactory;
+import org.apache.tuscany.sca.policy.PolicySet;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.NamedNodeMap;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+/**
+ * A base class with utility methods for the other artifact processors in this module. 
+ * 
+ * @version $Rev$ $Date$
+ */
+abstract class BaseAssemblyProcessor extends BaseStAXArtifactProcessor {
+
+    protected AssemblyFactory assemblyFactory;
+    protected PolicyFactory policyFactory;
+    protected StAXArtifactProcessor<Object> extensionProcessor;
+    protected PolicySubjectProcessor policyProcessor;
+    private DocumentBuilderFactory documentBuilderFactory;
+    private Monitor monitor;
+
+    /**
+     * Constructs a new BaseArtifactProcessor.
+     * @param assemblyFactory
+     * @param policyFactory
+     */
+    @SuppressWarnings("unchecked")
+    protected BaseAssemblyProcessor(AssemblyFactory assemblyFactory,
+                                    PolicyFactory policyFactory,
+                                    DocumentBuilderFactory documentBuilderFactory,
+                                    StAXArtifactProcessor extensionProcessor,
+                                    Monitor monitor) {
+        this.assemblyFactory = assemblyFactory;
+        this.policyFactory = policyFactory;
+        this.documentBuilderFactory = documentBuilderFactory;
+        this.extensionProcessor = (StAXArtifactProcessor<Object>)extensionProcessor;
+        this.policyProcessor = new PolicySubjectProcessor(policyFactory);
+        this.monitor = monitor;
+    }
+
+    /**
+     * @param modelFactories
+     * @param staxProcessor
+     * @param monitor
+     */
+    protected BaseAssemblyProcessor(FactoryExtensionPoint modelFactories,
+                                    StAXArtifactProcessor staxProcessor,
+                                    Monitor monitor) {
+        this.assemblyFactory = modelFactories.getFactory(AssemblyFactory.class);
+        this.policyFactory = modelFactories.getFactory(PolicyFactory.class);
+        this.documentBuilderFactory = modelFactories.getFactory(DocumentBuilderFactory.class);
+        this.extensionProcessor = (StAXArtifactProcessor<Object>)staxProcessor;
+        this.policyProcessor = new PolicySubjectProcessor(policyFactory);
+        this.monitor = monitor;
+    }
+
+    /**
+     * Marshals warnings into the monitor
+     * 
+     * @param message
+     * @param model
+     * @param messageParameters
+     */
+    protected void warning(String message, Object model, String... messageParameters) {
+        if (monitor != null) {
+            Problem problem =
+                monitor.createProblem(this.getClass().getName(),
+                                      "assembly-xml-validation-messages",
+                                      Severity.WARNING,
+                                      model,
+                                      message,
+                                      (Object[])messageParameters);
+            monitor.problem(problem);
+        }
+    }
+
+    /**
+     * Marshals errors into the monitor
+     * 
+     * @param problems
+     * @param message
+     * @param model
+     */
+    protected void error(String message, Object model, Object... messageParameters) {
+        if (monitor != null) {
+            Problem problem =
+                monitor.createProblem(this.getClass().getName(),
+                                      "assembly-xml-validation-messages",
+                                      Severity.ERROR,
+                                      model,
+                                      message,
+                                      (Object[])messageParameters);
+            monitor.problem(problem);
+        }
+    }
+
+    /**
+     * Marshals exceptions into the monitor
+     * 
+     * @param problems
+     * @param message
+     * @param model
+     */
+    protected void error(String message, Object model, Exception ex) {
+        if (monitor != null) {
+            Problem problem =
+                monitor.createProblem(this.getClass().getName(),
+                                      "assembly-xml-validation-messages",
+                                      Severity.ERROR,
+                                      model,
+                                      message,
+                                      ex);
+            monitor.problem(problem);
+        }
+    }
+
+    /**
+     * Start an element.
+     * @param writer
+     * @param name
+     * @param attrs
+     * @throws XMLStreamException
+     */
+    protected void writeStart(XMLStreamWriter writer, String name, XAttr... attrs) throws XMLStreamException {
+        writeStart(writer, SCA11_NS, name, attrs);
+    }
+
+    /**
+     * Start a document.
+     * @param writer
+     * @throws XMLStreamException
+     */
+    protected void writeStartDocument(XMLStreamWriter writer, String name, XAttr... attrs) throws XMLStreamException {
+        writer.writeStartDocument();
+        writer.setDefaultNamespace(SCA11_NS);
+        writeStart(writer, SCA11_NS, name, attrs);
+        writer.writeDefaultNamespace(SCA11_NS);
+    }
+
+    /**
+     * Read list of reference targets
+     * @param reference
+     * @param reader
+     */
+    protected void readTargets(Reference reference, XMLStreamReader reader) {
+        String value = reader.getAttributeValue(null, TARGET);
+        ComponentService target = null;
+        if (value != null) {
+            for (StringTokenizer tokens = new StringTokenizer(value); tokens.hasMoreTokens();) {
+                target = assemblyFactory.createComponentService();
+                target.setUnresolved(true);
+                target.setName(tokens.nextToken());
+                reference.getTargets().add(target);
+            }
+        }
+    }
+
+    /**
+     * Write a list of targets into an attribute
+     * @param reference
+     * @return
+     */
+    protected XAttr writeTargets(Reference reference) {
+        List<String> targets = new ArrayList<String>();
+        for (Service target : reference.getTargets()) {
+            targets.add(target.getName());
+        }
+        return new XAttr(TARGET, targets);
+    }
+
+    /**
+     * Read a multiplicity attribute.
+     * @param reference
+     * @param reader
+     */
+    protected void readMultiplicity(AbstractReference reference, XMLStreamReader reader) {
+        String value = reader.getAttributeValue(null, MULTIPLICITY);
+        if (ZERO_ONE.equals(value)) {
+            reference.setMultiplicity(Multiplicity.ZERO_ONE);
+        } else if (ONE_N.equals(value)) {
+            reference.setMultiplicity(Multiplicity.ONE_N);
+        } else if (ZERO_N.equals(value)) {
+            reference.setMultiplicity(Multiplicity.ZERO_N);
+        } else if (ONE_ONE.equals(value)) {
+            reference.setMultiplicity(Multiplicity.ONE_ONE);
+        }
+    }
+
+    protected XAttr writeMultiplicity(AbstractReference reference) {
+        Multiplicity multiplicity = reference.getMultiplicity();
+        if (multiplicity != null) {
+            String value = null;
+            if (Multiplicity.ZERO_ONE.equals(multiplicity)) {
+                value = ZERO_ONE;
+            } else if (Multiplicity.ONE_N.equals(multiplicity)) {
+                value = ONE_N;
+            } else if (Multiplicity.ZERO_N.equals(multiplicity)) {
+                value = ZERO_N;
+            } else if (Multiplicity.ONE_ONE.equals(multiplicity)) {
+                value = ONE_ONE;
+                return null;
+            }
+            return new XAttr(MULTIPLICITY, value);
+        }
+        return null;
+    }
+
+    /**
+     * Returns the value of a constrainingType attribute.
+     * @param reader
+     * @return
+     */
+    protected ConstrainingType readConstrainingType(XMLStreamReader reader) {
+        QName constrainingTypeName = getQName(reader, Constants.CONSTRAINING_TYPE);
+        if (constrainingTypeName != null) {
+            ConstrainingType constrainingType = assemblyFactory.createConstrainingType();
+            constrainingType.setName(constrainingTypeName);
+            constrainingType.setUnresolved(true);
+            return constrainingType;
+        } else {
+            return null;
+        }
+    }
+
+    /**
+     * Reads an abstract property element.
+     * @param property
+     * @param reader
+     * @throws XMLStreamException
+     * @throws ContributionReadException
+     */
+    protected void readAbstractProperty(AbstractProperty property, XMLStreamReader reader) throws XMLStreamException,
+        ContributionReadException {
+
+        property.setName(getString(reader, NAME));
+        property.setMany(getBoolean(reader, MANY));
+        property.setMustSupply(getBoolean(reader, MUST_SUPPLY));
+        property.setXSDElement(getQName(reader, ELEMENT));
+        property.setXSDType(getQName(reader, TYPE));
+
+    }
+
+    /**
+     * Resolve an implementation.
+     * @param implementation
+     * @param resolver
+     * @return
+     * @throws ContributionResolveException
+     */
+    protected Implementation resolveImplementation(Implementation implementation, ModelResolver resolver)
+        throws ContributionResolveException {
+        if (implementation != null) {
+            if (implementation.isUnresolved()) {
+                implementation = resolver.resolveModel(Implementation.class, implementation);
+
+                // Lazily resolve implementations
+                if (implementation.isUnresolved()) {
+                    extensionProcessor.resolve(implementation, resolver);
+                    if (!implementation.isUnresolved()) {
+                        resolver.addModel(implementation);
+                    }
+                }
+            }
+        }
+        return implementation;
+    }
+
+    /**
+     * Resolve interface, callback interface and bindings on a list of contracts.
+     * @param contracts the list of contracts
+     * @param resolver the resolver to use to resolve models
+     */
+    protected <C extends Contract> void resolveContracts(List<C> contracts, ModelResolver resolver)
+        throws ContributionResolveException {
+        resolveContracts(null, contracts, resolver);
+    }
+
+    /**
+     * Resolve interface, callback interface and bindings on a list of contracts.
+     * @param parent element for the contracts
+     * @param contracts the list of contracts
+     * @param resolver the resolver to use to resolve models
+     */
+    protected <C extends Contract> void resolveContracts(Base parent, List<C> contracts, ModelResolver resolver)
+        throws ContributionResolveException {
+
+        String parentName =
+            (parent instanceof Composite) ? ((Composite)parent).getName().toString() : (parent instanceof Component)
+                ? ((Component)parent).getName() : "UNKNOWN";
+
+        for (Contract contract : contracts) {
+            // Resolve the interface contract
+            InterfaceContract interfaceContract = contract.getInterfaceContract();
+            if (interfaceContract != null) {
+                extensionProcessor.resolve(interfaceContract, resolver);
+            }
+
+            // Resolve bindings
+            for (int i = 0, n = contract.getBindings().size(); i < n; i++) {
+                Binding binding = contract.getBindings().get(i);
+                extensionProcessor.resolve(binding, resolver);
+
+            }
+
+            // Resolve callback bindings
+            if (contract.getCallback() != null) {
+
+                for (int i = 0, n = contract.getCallback().getBindings().size(); i < n; i++) {
+                    Binding binding = contract.getCallback().getBindings().get(i);
+                    extensionProcessor.resolve(binding, resolver);
+                }
+            }
+        }
+    }
+
+    /**
+     * Resolve interface and callback interface on a list of abstract contracts.
+     * @param contracts the list of contracts
+     * @param resolver the resolver to use to resolve models
+     */
+    protected <C extends AbstractContract> void resolveAbstractContracts(List<C> contracts, ModelResolver resolver)
+        throws ContributionResolveException {
+        for (AbstractContract contract : contracts) {
+
+            // Resolve the interface contract
+            InterfaceContract interfaceContract = contract.getInterfaceContract();
+            if (interfaceContract != null) {
+                extensionProcessor.resolve(interfaceContract, resolver);
+            }
+        }
+    }
+
+    /**
+     * Returns a constrainingType attribute.
+     * @param componentType
+     * @return
+     */
+    protected XAttr writeConstrainingType(ComponentType componentType) {
+        ConstrainingType constrainingType = componentType.getConstrainingType();
+        if (constrainingType != null)
+            return new XAttr(Constants.CONSTRAINING_TYPE, constrainingType.getName());
+        else
+            return null;
+    }
+
+    /*
+    protected List<Extension> readPropertyValue(XMLStreamReader reader) throws XMLStreamException,
+        ContributionReadException {
+        List<Extension> values = new ArrayList<Extension>();
+        QName name = reader.getName(); // Should be sca:property
+
+        // SCA 1.1 supports the @value for simple types
+        String valueAttr = getString(reader, VALUE);
+        if (valueAttr != null) {
+            Extension ext = assemblyFactory.createExtension();
+            ext.setValue(valueAttr);
+            ext.setQName(VALUE_QNAME);
+            ext.setAttribute(true);
+            values.add(ext);
+        }
+
+        boolean isTextForProperty = true;
+        StringBuffer text = new StringBuffer();
+
+        int event = reader.getEventType();
+        while (true) {
+            switch (event) {
+                case START_ELEMENT:
+                    name = reader.getName();
+                    if (PROPERTY_QNAME.equals(name)) {
+                        isTextForProperty = true;
+                        break;
+                    }
+                    isTextForProperty = false;
+                    // Read <value>
+                    if (VALUE_QNAME.equals(name)) {
+                        Object value = extensionProcessor.read(reader);
+                        // Assume the value is the XMLStreamReader for the content
+                        Extension ext = assemblyFactory.createExtension();
+                        ext.setValue(value);
+                        ext.setQName(name);
+                        values.add(ext);
+                    } else {
+                        // Global elements
+                        // FIXME: do we want to check if the element mataches property.element
+                        Object value = extensionProcessor.read(reader);
+                        Extension ext = assemblyFactory.createExtension();
+                        ext.setValue(value);
+                        ext.setQName(name);
+                        values.add(ext);
+                    }
+                    break;
+                case XMLStreamConstants.CHARACTERS:
+                case XMLStreamConstants.CDATA:
+                    if (isTextForProperty) {
+                        text.append(reader.getText());
+                    }
+                    break;
+                case END_ELEMENT:
+                    name = reader.getName();
+                    if (PROPERTY_QNAME.equals(name)) {
+                        return values;
+                    }
+                    break;
+            }
+            if (reader.hasNext()) {
+                event = reader.next();
+            } else {
+                return values;
+            }
+        }
+    }
+    */
+    
+    /**
+     * Read a property value into a DOM document.
+     * @param element
+     * @param type
+     * @param reader
+     * @return
+     * @throws XMLStreamException
+     * @throws ContributionReadException
+     * @throws ParserConfigurationException 
+     */
+    protected Document readPropertyValue(QName element, QName type, XMLStreamReader reader) throws XMLStreamException,
+        ContributionReadException {
+        Document document;
+        try {
+            if (documentBuilderFactory == null) {
+                documentBuilderFactory = DocumentBuilderFactory.newInstance();
+                documentBuilderFactory.setNamespaceAware(true);
+            }
+            document = documentBuilderFactory.newDocumentBuilder().newDocument();
+        } catch (ParserConfigurationException e) {
+            ContributionReadException ce = new ContributionReadException(e);
+            error("ContributionReadException", documentBuilderFactory, ce);
+            throw ce;
+        }
+
+        // Collect the property values as <value> elements under the <property>
+        Element root = document.createElementNS(SCA11_NS, "sca:" + PROPERTY);
+        String nameAttr = getString(reader, NAME);
+        if (nameAttr != null) {
+            root.setAttributeNS(SCA11_NS, "sca:" + NAME, nameAttr);
+        }
+        declareNamespace(root, "sca", SCA11_NS);
+        if (type != null) {
+            org.w3c.dom.Attr xsi = document.createAttributeNS(XMLNS_ATTRIBUTE_NS_URI, "xmlns:xsi");
+            xsi.setValue(W3C_XML_SCHEMA_INSTANCE_NS_URI);
+            root.setAttributeNodeNS(xsi);
+
+            String prefix = type.getPrefix();
+            if (prefix == null || prefix.length() == 0) {
+                prefix = "ns";
+            }
+
+            declareNamespace(root, prefix, type.getNamespaceURI());
+
+            org.w3c.dom.Attr xsiType = document.createAttributeNS(W3C_XML_SCHEMA_INSTANCE_NS_URI, "xsi:type");
+            xsiType.setValue(prefix + ":" + type.getLocalPart());
+            root.setAttributeNodeNS(xsiType);
+        }
+        document.appendChild(root);
+
+        // Start to parse the property
+        QName name = reader.getName(); // Should be sca:property
+
+        // SCA 1.1 supports the @value for simple types
+        String valueAttr = getString(reader, VALUE);
+        if (valueAttr != null) {
+            Element valueElement = document.createElementNS(SCA11_NS, VALUE);
+            root.appendChild(valueElement);
+            valueElement.setTextContent(valueAttr);
+        }
+
+        boolean isTextForProperty = true;
+        StringBuffer text = new StringBuffer();
+
+        int event = reader.getEventType();
+        while (true) {
+            switch (event) {
+                case START_ELEMENT:
+                    name = reader.getName();
+                    if (PROPERTY_QNAME.equals(name)) {
+                        isTextForProperty = true;
+                        break;
+                    }
+                    isTextForProperty = false;
+                    // Read <value>
+                    if (VALUE_QNAME.equals(name)) {
+                        loadElement(reader, root);
+                    } else {
+                        // Global elements
+                        loadElement(reader, root);
+                    }
+                    break;
+                case XMLStreamConstants.CHARACTERS:
+                case XMLStreamConstants.CDATA:
+                    if (isTextForProperty) {
+                        text.append(reader.getText());
+                    }
+                    break;
+                case END_ELEMENT:
+                    name = reader.getName();
+                    if (PROPERTY_QNAME.equals(name)) {
+                        if (root.getChildNodes().getLength() == 0) {
+                            // Add the text as an <value>
+                            Element valueElement = document.createElementNS(SCA11_NS, VALUE);
+                            root.appendChild(valueElement);
+                            valueElement.setTextContent(text.toString());
+                        }
+                        return document;
+                    }
+                    break;
+            }
+            if (reader.hasNext()) {
+                event = reader.next();
+            } else {
+                break;
+            }
+        }
+        return document;
+    }
+
+    /**
+     * Create a DOM element
+     * @param document
+     * @param name
+     * @return
+     */
+    private Element createElement(Document document, QName name) {
+        String prefix = name.getPrefix();
+        String qname =
+            (prefix != null && prefix.length() > 0) ? prefix + ":" + name.getLocalPart() : name.getLocalPart();
+        return document.createElementNS(name.getNamespaceURI(), qname);
+    }
+
+    /**
+     * Declare a namespace.
+     * @param element
+     * @param prefix
+     * @param ns
+     */
+    private void declareNamespace(Element element, String prefix, String ns) {
+        if (ns == null) {
+            ns = "";
+        }
+        if (prefix == null) {
+            prefix = "";
+        }
+        String qname = null;
+        if ("".equals(prefix)) {
+            qname = "xmlns";
+        } else {
+            qname = "xmlns:" + prefix;
+        }
+        Node node = element;
+        boolean declared = false;
+        while (node != null && node.getNodeType() == Node.ELEMENT_NODE) {
+            NamedNodeMap attrs = node.getAttributes();
+            if (attrs == null) {
+                break;
+            }
+            Node attr = attrs.getNamedItem(qname);
+            if (attr != null) {
+                declared = ns.equals(attr.getNodeValue());
+                break;
+            }
+            node = node.getParentNode();
+        }
+        if (!declared) {
+            org.w3c.dom.Attr attr = element.getOwnerDocument().createAttributeNS(XMLNS_ATTRIBUTE_NS_URI, qname);
+            attr.setValue(ns);
+            element.setAttributeNodeNS(attr);
+        }
+    }
+
+    /**
+     * Load a property value specification from an StAX stream into a DOM
+     * Document. Only elements, text and attributes are processed; all comments
+     * and other whitespace are ignored.
+     * 
+     * @param reader the stream to read from
+     * @param root the DOM node to load
+     * @throws javax.xml.stream.XMLStreamException
+     */
+    private void loadElement(XMLStreamReader reader, Element root) throws XMLStreamException {
+        Document document = root.getOwnerDocument();
+        Node current = root;
+        while (true) {
+            switch (reader.getEventType()) {
+                case START_ELEMENT:
+                    QName name = reader.getName();
+                    Element child = createElement(document, name);
+
+                    // push the new element and make it the current one
+                    current.appendChild(child);
+                    current = child;
+
+                    int count = reader.getNamespaceCount();
+                    for (int i = 0; i < count; i++) {
+                        String prefix = reader.getNamespacePrefix(i);
+                        String ns = reader.getNamespaceURI(i);
+                        declareNamespace(child, prefix, ns);
+                    }
+
+                    if (!"".equals(name.getNamespaceURI())) {
+                        declareNamespace(child, name.getPrefix(), name.getNamespaceURI());
+                    }
+
+                    // add the attributes for this element
+                    count = reader.getAttributeCount();
+                    for (int i = 0; i < count; i++) {
+                        String ns = reader.getAttributeNamespace(i);
+                        String prefix = reader.getAttributePrefix(i);
+                        String qname = reader.getAttributeLocalName(i);
+                        String value = reader.getAttributeValue(i);
+                        if (prefix != null && prefix.length() != 0) {
+                            qname = prefix + ":" + qname;
+                        }
+                        child.setAttributeNS(ns, qname, value);
+                        if (ns != null) {
+                            declareNamespace(child, prefix, ns);
+                        }
+                    }
+
+                    break;
+                case CDATA:
+                    current.appendChild(document.createCDATASection(reader.getText()));
+                    break;
+                case CHARACTERS:
+                    current.appendChild(document.createTextNode(reader.getText()));
+                    break;
+                case COMMENT:
+                    current.appendChild(document.createComment(reader.getText()));
+                    break;
+                case END_ELEMENT:
+                    // pop the element off the stack
+                    current = current.getParentNode();
+                    // if we are back at the root then we are done
+                    if (current == root) {
+                        return;
+                    }
+
+            }
+            if (reader.hasNext()) {
+                reader.next();
+            } else {
+                return;
+            }
+        }
+    }
+
+    /**
+     * Write the value of a property 
+     * @param document
+     * @param element
+     * @param type
+     * @param writer
+     * @throws XMLStreamException
+     */
+    protected void writePropertyValue(Object propertyValue, QName element, QName type, XMLStreamWriter writer)
+        throws XMLStreamException {
+
+        if (propertyValue instanceof Document) {
+            Document document = (Document)propertyValue;
+            NodeList nodeList = document.getDocumentElement().getChildNodes();
+
+            for (int item = 0; item < nodeList.getLength(); ++item) {
+                Node node = nodeList.item(item);
+                int nodeType = node.getNodeType();
+                if (nodeType == Node.ELEMENT_NODE) {
+                    XMLStreamReader reader = XMLInputFactory.newInstance().createXMLStreamReader(new DOMSource(node));
+
+                    while (reader.hasNext()) {
+                        switch (reader.next()) {
+                            case XMLStreamConstants.START_ELEMENT:
+                                QName name = reader.getName();
+                                writer.writeStartElement(name.getPrefix(), name.getLocalPart(), name.getNamespaceURI());
+
+                                int namespaces = reader.getNamespaceCount();
+                                for (int i = 0; i < namespaces; i++) {
+                                    String prefix = reader.getNamespacePrefix(i);
+                                    String ns = reader.getNamespaceURI(i);
+                                    writer.writeNamespace(prefix, ns);
+                                }
+
+                                if (!"".equals(name.getNamespaceURI())) {
+                                    writer.writeNamespace(name.getPrefix(), name.getNamespaceURI());
+                                }
+
+                                // add the attributes for this element
+                                namespaces = reader.getAttributeCount();
+                                for (int i = 0; i < namespaces; i++) {
+                                    String ns = reader.getAttributeNamespace(i);
+                                    String prefix = reader.getAttributePrefix(i);
+                                    String qname = reader.getAttributeLocalName(i);
+                                    String value = reader.getAttributeValue(i);
+
+                                    writer.writeAttribute(prefix, ns, qname, value);
+                                }
+
+                                break;
+                            case XMLStreamConstants.CDATA:
+                                writer.writeCData(reader.getText());
+                                break;
+                            case XMLStreamConstants.CHARACTERS:
+                                writer.writeCharacters(reader.getText());
+                                break;
+                            case XMLStreamConstants.END_ELEMENT:
+                                writer.writeEndElement();
+                                break;
+                        }
+                    }
+                } else {
+                    writer.writeCharacters(node.getTextContent());
+                }
+            }
+        }
+    }
+
+    protected void addInheritedIntents(List<Intent> sourceList, List<Intent> targetList) {
+        if (sourceList != null) {
+            targetList.addAll(sourceList);
+        }
+    }
+
+    protected void addInheritedPolicySets(List<PolicySet> sourceList, List<PolicySet> targetList) {
+        if (sourceList != null) {
+            targetList.addAll(sourceList);
+        }
+    }
+
+    /**
+     * 
+     * @param reader
+     * @param elementName
+     * @param estensibleElement
+     * @param extensionAttributeProcessor
+     * @throws ContributionReadException
+     * @throws XMLStreamException
+     */
+    protected void readExtendedAttributes(XMLStreamReader reader,
+                                          QName elementName,
+                                          Extensible estensibleElement,
+                                          StAXAttributeProcessor extensionAttributeProcessor)
+        throws ContributionReadException, XMLStreamException {
+        for (int a = 0; a < reader.getAttributeCount(); a++) {
+            QName attributeName = reader.getAttributeName(a);
+            if (attributeName.getNamespaceURI() != null && attributeName.getNamespaceURI().length() > 0) {
+                if (!elementName.getNamespaceURI().equals(attributeName.getNamespaceURI())) {
+                    Object attributeValue = extensionAttributeProcessor.read(attributeName, reader);
+                    Extension attributeExtension;
+                    if (attributeValue instanceof Extension) {
+                        attributeExtension = (Extension)attributeValue;
+                    } else {
+                        attributeExtension = assemblyFactory.createExtension();
+                        attributeExtension.setQName(attributeName);
+                        attributeExtension.setAttribute(true);
+                        attributeExtension.setValue(attributeValue);
+                    }
+                    estensibleElement.getAttributeExtensions().add(attributeExtension);
+                }
+            }
+        }
+    }
+
+    /**
+     * 
+     * @param attributeModel
+     * @param writer
+     * @param extensibleElement
+     * @param extensionAttributeProcessor
+     * @throws ContributionWriteException
+     * @throws XMLStreamException
+     */
+    protected void writeExtendedAttributes(XMLStreamWriter writer,
+                                           Extensible extensibleElement,
+                                           StAXAttributeProcessor extensionAttributeProcessor)
+        throws ContributionWriteException, XMLStreamException {
+        for (Extension extension : extensibleElement.getAttributeExtensions()) {
+            if (extension.isAttribute()) {
+                extensionAttributeProcessor.write(extension, writer);
+            }
+        }
+    }
+
+    /*protected void validatePolicySets(PolicySubject policySetAttachPoint) 
+                                                            throws ContributionResolveException {
+        validatePolicySets(policySetAttachPoint, policySetAttachPoint.getApplicablePolicySets());
+    }
+     
+    
+    protected void validatePolicySets(PolicySubject policySetAttachPoint,
+                                      List<PolicySet> applicablePolicySets) throws ContributionResolveException {
+        //Since the applicablePolicySets in a policySetAttachPoint will already have the 
+        //list of policysets that might ever be applicable to this attachPoint, just check
+        //if the defined policysets feature in the list of applicable policysets
+        ExtensionType attachPointType = policySetAttachPoint.getType();
+        for ( PolicySet definedPolicySet : policySetAttachPoint.getPolicySets() ) {
+            if ( !definedPolicySet.isUnresolved() ) {
+                if ( !applicablePolicySets.contains(definedPolicySet)) {
+                    throw new ContributionResolveException("Policy Set '" + definedPolicySet.getName()
+                                                           + "' does not apply to binding type  "
+                                                           + attachPointType.getName());
+                }
+            } else {
+                throw new ContributionResolveException("Policy Set '" + definedPolicySet.getName()
+                                                       + "' is not defined in this domain  ");
+                                                
+            
+            }
+        }
+    }*/
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeDocumentProcessor.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeDocumentProcessor.java
new file mode 100644
index 0000000000..969115cf4c
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeDocumentProcessor.java
@@ -0,0 +1,130 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.net.URL;
+import java.net.URLConnection;
+
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+
+import org.apache.tuscany.sca.assembly.ComponentType;
+import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
+import org.apache.tuscany.sca.contribution.processor.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.URLArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.ValidatingXMLInputFactory;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.monitor.Monitor;
+
+/**
+ * A componentType processor.
+ * 
+ * @version $Rev$ $Date$
+ */
+public class ComponentTypeDocumentProcessor extends BaseAssemblyProcessor implements URLArtifactProcessor<ComponentType> {
+    private XMLInputFactory inputFactory;
+    
+    /**
+     * Constructs a new componentType processor.
+     * @param modelFactories
+     * @param staxProcessor
+     */
+    public ComponentTypeDocumentProcessor(FactoryExtensionPoint modelFactories,
+                                          StAXArtifactProcessor staxProcessor,
+                                          Monitor monitor) {
+        super(modelFactories, staxProcessor, monitor);
+        this.inputFactory = modelFactories.getFactory(ValidatingXMLInputFactory.class);
+    }
+    
+    public ComponentType read(URL contributionURL, URI uri, URL url) throws ContributionReadException {
+        InputStream urlStream = null;
+        try {
+            
+            // Create a stream reader
+            URLConnection connection = url.openConnection();
+            connection.setUseCaches(false);
+            urlStream = connection.getInputStream();
+            XMLStreamReader reader = inputFactory.createXMLStreamReader(url.toString(), urlStream);
+            reader.nextTag();
+            
+            // Reader the componentType model 
+            ComponentType componentType = (ComponentType)extensionProcessor.read(reader);
+            if (componentType != null) {
+                componentType.setURI(uri.toString());
+            }
+
+            // For debugging purposes, write it back to XML
+//            if (componentType != null) {
+//                try {
+//                    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+//                    XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();
+//                    outputFactory.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, Boolean.TRUE);
+//                    extensionProcessor.write(componentType, outputFactory.createXMLStreamWriter(bos));
+//                    Document document = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new ByteArrayInputStream(bos.toByteArray()));
+//                    OutputFormat format = new OutputFormat();
+//                    format.setIndenting(true);
+//                    format.setIndent(2);
+//                    XMLSerializer serializer = new XMLSerializer(System.out, format);
+//                    serializer.serialize(document);
+//                } catch (Exception e) {
+//                    e.printStackTrace();
+//                }
+//            }
+            
+            return componentType;
+            
+        } catch (XMLStreamException e) {
+        	ContributionReadException ce = new ContributionReadException(e);
+        	error("ContributionReadException", inputFactory, ce);
+            throw ce;
+        } catch (IOException e) {
+        	ContributionReadException ce = new ContributionReadException(e);
+        	error("ContributionReadException", inputFactory, ce);
+            throw ce;
+        } finally {
+            try {
+                if (urlStream != null) {
+                    urlStream.close();
+                    urlStream = null;
+                }
+            } catch (IOException ioe) {
+                //ignore
+            }
+        }
+    }
+    
+    public void resolve(ComponentType componentType, ModelResolver resolver) throws ContributionResolveException {
+        extensionProcessor.resolve(componentType, resolver);
+    }
+    
+    public String getArtifactType() {
+        return ".componentType";
+    }
+    
+    public Class<ComponentType> getModelType() {
+        return ComponentType.class;
+    }
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeModelResolver.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeModelResolver.java
new file mode 100644
index 0000000000..166bba8757
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeModelResolver.java
@@ -0,0 +1,95 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.tuscany.sca.assembly.ComponentType;
+import org.apache.tuscany.sca.contribution.Contribution;
+import org.apache.tuscany.sca.contribution.Import;
+import org.apache.tuscany.sca.contribution.java.JavaImport;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+
+/**
+ * A Model Resolver for ComponentType models.
+ *
+ * @version $Rev$ $Date$
+ */
+public class ComponentTypeModelResolver implements ModelResolver {
+	private Contribution contribution;
+    private Map<String, ComponentType> map = new HashMap<String, ComponentType>();
+    
+    public ComponentTypeModelResolver(Contribution contribution, FactoryExtensionPoint modelFactories) {
+    	this.contribution = contribution;
+    }
+
+    public void addModel(Object resolved) {
+        ComponentType componentType = (ComponentType)resolved;
+        map.put(componentType.getURI(), componentType);
+    }
+    
+    public Object removeModel(Object resolved) {
+        return map.remove(((ComponentType)resolved).getURI());
+    }
+    
+    public <T> T resolveModel(Class<T> modelClass, T unresolved) {
+
+    	//get componentType artifact URI
+        String uri = ((ComponentType)unresolved).getURI();
+        if (uri == null) {
+        	return (T)unresolved;
+        }
+        
+        //lookup the componentType
+        ComponentType resolved = (ComponentType) map.get(uri);
+        if (resolved != null) {
+            return modelClass.cast(resolved);
+        } 
+        
+        //If not found, delegate the resolution to the imports (in this case based on the java imports)
+        //compute the package name from the componentType URI
+        if (unresolved instanceof ComponentType) {
+            //FIXME The core assembly model now depends on java imports to 
+            // resolve componentTypes of all kinds, this is not right at all!!!
+            int s = uri.lastIndexOf('/');
+            if (s != -1) {
+                String packageName = uri.substring(0, uri.lastIndexOf("/"));
+                for (Import import_ : this.contribution.getImports()) {
+                    if (import_ instanceof JavaImport) {
+                    	JavaImport javaImport = (JavaImport)import_;
+                    	//check the import location against the computed package name from the componentType URI
+                        if (javaImport.getPackage().equals(packageName)) {
+                            // Delegate the resolution to the import resolver
+                            resolved = javaImport.getModelResolver().resolveModel(ComponentType.class, (ComponentType)unresolved);
+                            if (!resolved.isUnresolved()) {
+                                return modelClass.cast(resolved);
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        return (T)unresolved;
+    }
+    
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeProcessor.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeProcessor.java
new file mode 100644
index 0000000000..0ea78177ff
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeProcessor.java
@@ -0,0 +1,381 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import static javax.xml.stream.XMLStreamConstants.END_ELEMENT;
+import static javax.xml.stream.XMLStreamConstants.START_ELEMENT;
+import static org.apache.tuscany.sca.assembly.xml.Constants.CALLBACK;
+import static org.apache.tuscany.sca.assembly.xml.Constants.CALLBACK_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.COMPONENT_TYPE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.COMPONENT_TYPE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.ELEMENT;
+import static org.apache.tuscany.sca.assembly.xml.Constants.IMPLEMENTATION;
+import static org.apache.tuscany.sca.assembly.xml.Constants.MANY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.MUST_SUPPLY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.NAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.OPERATION_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.PROPERTY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.PROPERTY_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.REFERENCE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.REFERENCE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.SERVICE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.SERVICE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.TYPE;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+
+import org.apache.tuscany.sca.assembly.Binding;
+import org.apache.tuscany.sca.assembly.Callback;
+import org.apache.tuscany.sca.assembly.ComponentType;
+import org.apache.tuscany.sca.assembly.Contract;
+import org.apache.tuscany.sca.assembly.Extensible;
+import org.apache.tuscany.sca.assembly.Property;
+import org.apache.tuscany.sca.assembly.Reference;
+import org.apache.tuscany.sca.assembly.Service;
+import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
+import org.apache.tuscany.sca.contribution.processor.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.processor.ContributionWriteException;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.StAXAttributeProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.interfacedef.InterfaceContract;
+import org.apache.tuscany.sca.interfacedef.Operation;
+import org.apache.tuscany.sca.interfacedef.impl.OperationImpl;
+import org.apache.tuscany.sca.monitor.Monitor;
+import org.apache.tuscany.sca.policy.PolicySubject;
+import org.w3c.dom.Document;
+
+/**
+ * A componentType processor.
+ * 
+ * @version $Rev$ $Date$
+ */
+public class ComponentTypeProcessor extends BaseAssemblyProcessor implements StAXArtifactProcessor<ComponentType> {
+    
+    /**
+     * Constructs a new componentType processor.
+     * 
+     * @param modelFactories
+     * @param extensionProcessor
+     * @param extensionAttributeProcessor
+     * @param monitor
+     */
+    public ComponentTypeProcessor(FactoryExtensionPoint modelFactories,
+                                  StAXArtifactProcessor extensionProcessor,
+                                  StAXAttributeProcessor extensionAttributeProcessor,
+                                  Monitor monitor) {
+        super(modelFactories, extensionProcessor, monitor);
+    }
+    
+    public ComponentType read(XMLStreamReader reader) throws ContributionReadException {
+        ComponentType componentType = null;
+        Service service = null;
+        Reference reference = null;
+        Contract contract = null;
+        Property property = null;
+        Callback callback = null;
+        QName name = null;
+        
+        try {
+            // Read the componentType document
+            while (reader.hasNext()) {
+                int event = reader.getEventType();
+                switch (event) {
+                    case START_ELEMENT:
+                        name = reader.getName();
+    
+                        if (Constants.COMPONENT_TYPE_QNAME.equals(name)) {
+    
+                            // Read a <componentType>
+                            componentType = assemblyFactory.createComponentType();
+                            componentType.setConstrainingType(readConstrainingType(reader));
+    
+                        } else if (Constants.SERVICE_QNAME.equals(name)) {
+    
+                            // Read a <service>
+                            service = assemblyFactory.createService();
+                            contract = service;
+                            service.setName(getString(reader, Constants.NAME));
+                            componentType.getServices().add(service);
+                            policyProcessor.readPolicies(service, reader);
+    
+                        } else if (Constants.REFERENCE_QNAME.equals(name)) {
+    
+                            // Read a <reference>
+                            reference = assemblyFactory.createReference();
+                            contract = reference;
+                            reference.setName(getString(reader, Constants.NAME));
+                            reference.setWiredByImpl(getBoolean(reader, Constants.WIRED_BY_IMPL));
+                            readMultiplicity(reference, reader);
+                            readTargets(reference, reader);
+                            componentType.getReferences().add(reference);
+                            policyProcessor.readPolicies(reference, reader);
+    
+                        } else if (Constants.PROPERTY_QNAME.equals(name)) {
+    
+                            // Read a <property>
+                            property = assemblyFactory.createProperty();
+                            readAbstractProperty(property, reader);
+                            policyProcessor.readPolicies(property, reader);
+                            
+                            // Read the property value
+                            Document value = readPropertyValue(property.getXSDElement(), property.getXSDType(), reader);
+                            property.setValue(value);
+                            
+                            componentType.getProperties().add(property);
+                            
+                        } else if (Constants.IMPLEMENTATION_QNAME.equals(name)) {
+                            
+                            // Read an <implementation> element
+                            policyProcessor.readPolicies(componentType, reader);
+                            
+                        } else if (Constants.CALLBACK_QNAME.equals(name)) {
+    
+                            // Read a <callback>
+                            callback = assemblyFactory.createCallback();
+                            contract.setCallback(callback);
+                            policyProcessor.readPolicies(callback, reader);
+    
+                        } else if (OPERATION_QNAME.equals(name)) {
+    
+                            // Read an <operation>
+                            Operation operation = new OperationImpl();
+                            operation.setName(getString(reader, NAME));
+                            operation.setUnresolved(true);
+                            if (callback != null) {
+                                policyProcessor.readPolicies(callback, operation, reader);
+                            } else {
+                                policyProcessor.readPolicies(contract, operation, reader);
+                            }
+                        } else {
+    
+                            // Read an extension element
+                            Object extension = extensionProcessor.read(reader);
+                            if (extension != null) {
+                                if (extension instanceof InterfaceContract) {
+    
+                                    // <service><interface> and <reference><interface>
+                                    contract.setInterfaceContract((InterfaceContract)extension);
+    
+                                } else if (extension instanceof Binding) {
+    
+                                    // <service><binding> and <reference><binding>
+                                    if (callback != null) {
+                                        callback.getBindings().add((Binding)extension);
+                                    } else {
+                                        contract.getBindings().add((Binding)extension);
+                                    }
+                                } else {
+                                    
+                                    // Add the extension element to the current element
+                                    if (callback != null) {
+                                        callback.getExtensions().add(extension);
+                                    } else if (contract != null) {
+                                        contract.getExtensions().add(extension);
+                                    } else if (property != null) {
+                                        property.getExtensions().add(extension);
+                                    } else {
+                                        if (componentType instanceof Extensible) {
+                                            ((Extensible)componentType).getExtensions().add(extension);
+                                        }
+                                    }
+                                }
+                            }
+                        }
+                        break;
+    
+                    case END_ELEMENT:
+                        name = reader.getName();
+    
+                        // Clear current state when reading reaching end element
+                        if (SERVICE_QNAME.equals(name)) {
+                            service = null;
+                            contract = null;
+                        } else if (REFERENCE_QNAME.equals(name)) {
+                            reference = null;
+                            contract = null;
+                        } else if (PROPERTY_QNAME.equals(name)) {
+                            property = null;
+                        } else if (CALLBACK_QNAME.equals(name)) {
+                            callback = null;
+                        }
+                        break;
+                }
+                
+                // Read the next element
+                if (reader.hasNext()) {
+                    reader.next();
+                }
+            }
+        }
+        catch (XMLStreamException e) {
+            ContributionReadException ex = new ContributionReadException(e);
+            error("XMLStreamException", reader, ex);
+        }
+        
+        return componentType;
+    }
+    
+    public void write(ComponentType componentType, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {
+        
+        // Write <componentType> element
+        writeStartDocument(writer, COMPONENT_TYPE,
+               writeConstrainingType(componentType));
+
+        // Write <service> elements
+        for (Service service : componentType.getServices()) {
+            writeStart(writer, SERVICE, new XAttr(NAME, service.getName()),
+                       policyProcessor.writePolicies(service));
+
+            if (service.getInterfaceContract() != null) {
+                extensionProcessor.write(service.getInterfaceContract(), writer);
+            }
+            
+            for (Binding binding: service.getBindings()) {
+                extensionProcessor.write(binding, writer);
+            }
+            
+            if (service.getCallback() != null) {
+                Callback callback = service.getCallback();
+                writeStart(writer, CALLBACK, policyProcessor.writePolicies(callback));
+
+                for (Binding binding: callback.getBindings()) {
+                    extensionProcessor.write(binding, writer);
+                }
+                for (Object extension: callback.getExtensions()) {
+                    extensionProcessor.write(extension, writer);
+                }
+                
+                writeEnd(writer);
+            }
+            
+            for (Object extension: service.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+            
+            writeEnd(writer);
+        }
+
+        // Write <reference> elements
+        for (Reference reference : componentType.getReferences()) {
+            
+            writeStart(writer, REFERENCE,
+                  new XAttr(NAME, reference.getName()),
+                  writeMultiplicity(reference),
+                  writeTargets(reference),
+                  policyProcessor.writePolicies(reference));
+
+            extensionProcessor.write(reference.getInterfaceContract(), writer);
+            
+            for (Binding binding: reference.getBindings()) {
+                extensionProcessor.write(binding, writer);
+            }
+            
+            if (reference.getCallback() != null) {
+                Callback callback = reference.getCallback();
+                writeStart(writer, CALLBACK,
+                           policyProcessor.writePolicies(callback));
+
+                for (Binding binding: callback.getBindings()) {
+                    extensionProcessor.write(binding, writer);
+                }
+                for (Object extension: callback.getExtensions()) {
+                    extensionProcessor.write(extension, writer);
+                }
+                
+                writeEnd(writer);
+            }
+
+            for (Object extension: reference.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+            
+            writeEnd(writer);
+        }
+
+        // Write <property> elements
+        for (Property property : componentType.getProperties()) {
+            writeStart(writer,
+                       PROPERTY,
+                       new XAttr(NAME, property.getName()),
+                       new XAttr(MUST_SUPPLY, property.isMustSupply()),
+                       new XAttr(MANY, property.isMany()),
+                       new XAttr(TYPE, property.getXSDType()),
+                       new XAttr(ELEMENT, property.getXSDElement()),
+                       policyProcessor.writePolicies(property));
+
+            // Write property value
+            writePropertyValue(property.getValue(), property.getXSDElement(), property.getXSDType(), writer);
+
+            // Write extensions
+            for (Object extension : property.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+
+            writeEnd(writer);
+        }
+
+        // Write extension elements
+        if (componentType instanceof Extensible) {
+            for (Object extension: ((Extensible)componentType).getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+        }
+        
+        // Write <implementation> elements if the componentType has
+        // any intents or policySets
+        boolean writeImplementation = false;
+        if (componentType instanceof PolicySubject) {
+            if (!((PolicySubject)componentType).getRequiredIntents().isEmpty()) {
+                writeImplementation = true;
+            }
+        }
+        if (componentType instanceof PolicySubject) {
+            if (!((PolicySubject)componentType).getPolicySets().isEmpty()) {
+                writeImplementation = true;
+            }
+        }
+        if (writeImplementation) {
+            writeStart(writer, IMPLEMENTATION,
+                       policyProcessor.writePolicies(componentType));
+        }
+        
+        writeEndDocument(writer);
+    }
+    
+    public void resolve(ComponentType componentType, ModelResolver resolver) throws ContributionResolveException {
+
+        // Resolve component type services and references
+        resolveContracts(componentType.getServices(), resolver);
+        resolveContracts(componentType.getReferences(), resolver);
+    }
+    
+    public QName getArtifactType() {
+        return COMPONENT_TYPE_QNAME;
+    }
+    
+    public Class<ComponentType> getModelType() {
+        return ComponentType.class;
+    }
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeDocumentProcessor.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeDocumentProcessor.java
new file mode 100644
index 0000000000..b6182e3950
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeDocumentProcessor.java
@@ -0,0 +1,202 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import java.io.ByteArrayInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.net.URL;
+import java.net.URLConnection;
+import java.util.Collection;
+import java.util.List;
+
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+
+import org.apache.tuscany.sca.assembly.Composite;
+import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
+import org.apache.tuscany.sca.contribution.processor.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.URLArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.ValidatingXMLInputFactory;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.monitor.Monitor;
+import org.apache.tuscany.sca.policy.PolicySet;
+import org.apache.tuscany.sca.policy.util.PolicyComputationUtils;
+
+/**
+ * A composite processor.
+ * 
+ * @version $Rev$ $Date$
+ */
+public class CompositeDocumentProcessor extends BaseAssemblyProcessor implements URLArtifactProcessor<Composite> {
+    private XMLInputFactory inputFactory;
+    private DocumentBuilderFactory documentBuilderFactory;
+    private List scaDefnSink;
+    private Collection<PolicySet> domainPolicySets = null;
+    private int scaDefnsCount = 0;
+
+    /**
+     * Constructs a new composite processor.
+     * @param modelFactories
+     * @param staxProcessor
+     */
+    public CompositeDocumentProcessor(FactoryExtensionPoint modelFactories,
+                                      StAXArtifactProcessor staxProcessor,
+                                      Monitor monitor) {
+        super(modelFactories, staxProcessor, monitor);
+        this.inputFactory = modelFactories.getFactory(ValidatingXMLInputFactory.class);
+        this.documentBuilderFactory = modelFactories.getFactory(DocumentBuilderFactory.class);
+    }
+    
+    public Composite read(URL contributionURL, URI uri, URL url) throws ContributionReadException {
+        InputStream scdlStream = null;
+        try {
+            URLConnection connection = url.openConnection();
+            connection.setUseCaches(false);
+            scdlStream = connection.getInputStream();
+        } catch (IOException e) {
+            ContributionReadException ce = new ContributionReadException(e);
+            error("ContributionReadException", url, ce);
+            throw ce;
+        }
+        return read(uri, scdlStream);
+    }
+
+    public Composite read(URI uri, InputStream scdlStream) throws ContributionReadException {
+        try {
+/*            
+            if (scaDefnSink != null ) {
+                fillDomainPolicySets(scaDefnSink);
+            }
+*/            
+            
+            Composite composite = null;
+            
+            byte[] transformedArtifactContent;
+            try {
+                if ( domainPolicySets != null ) {
+                    transformedArtifactContent =
+                        PolicyComputationUtils.addApplicablePolicySets(scdlStream, domainPolicySets, documentBuilderFactory);
+                    scdlStream = new ByteArrayInputStream(transformedArtifactContent);
+                } 
+            } catch ( IOException e ) {
+            	ContributionReadException ce = new ContributionReadException(e);
+            	error("ContributionReadException", scdlStream, ce);
+            	throw ce;
+            } catch ( Exception e ) {
+            	ContributionReadException ce = new ContributionReadException(e);
+            	error("ContributionReadException", scdlStream, ce);
+                //throw ce;
+            }
+            
+            XMLStreamReader reader = inputFactory.createXMLStreamReader(scdlStream);
+            
+            reader.nextTag();
+            
+            // Read the composite model
+            composite = (Composite)extensionProcessor.read(reader);
+            if (composite != null) {
+                composite.setURI(uri.toString());
+            }
+
+            // For debugging purposes, write it back to XML
+//            if (composite != null) {
+//                try {
+//                    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+//                    XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();
+//                    outputFactory.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, Boolean.TRUE);
+//                    extensionProcessor.write(composite, outputFactory.createXMLStreamWriter(bos));
+//                    Document document = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new ByteArrayInputStream(bos.toByteArray()));
+//                    OutputFormat format = new OutputFormat();
+//                    format.setIndenting(true);
+//                    format.setIndent(2);
+//                    XMLSerializer serializer = new XMLSerializer(System.out, format);
+//                    serializer.serialize(document);
+//                } catch (Exception e) {
+//                    e.printStackTrace();
+//                }
+//            }
+            
+            return composite;
+            
+        } catch (XMLStreamException e) {
+        	ContributionReadException ce = new ContributionReadException(e);
+        	error("ContributionReadException", inputFactory, ce);
+            throw ce;
+        } finally {
+            try {
+                if (scdlStream != null) {
+                    scdlStream.close();
+                    scdlStream = null;
+                }
+            } catch (IOException ioe) {
+                //ignore
+            }
+        }
+    }
+    
+    public void resolve(Composite composite, ModelResolver resolver) throws ContributionResolveException {
+        if (composite != null)
+    	    extensionProcessor.resolve(composite, resolver);
+    }
+
+    public String getArtifactType() {
+        return ".composite";
+    }
+    
+    public Class<Composite> getModelType() {
+        return Composite.class;
+    }
+    
+    /* 
+     * TODO - remove - definitions information is now aggregated in the 
+     *        systems definitions contribution and we need to add 
+     *        applicable policy sets once all composites have been read
+    private void fillDomainPolicySets(List scaDefnsSink) {
+        Map<QName, PolicySet> domainPolicySetMap = null;
+        if ( scaDefnsSink.size() > scaDefnsCount ) {
+        //if ( !scaDefnsSink.isEmpty() ) {
+            domainPolicySetMap = new Hashtable<QName, PolicySet>();
+            
+            if ( domainPolicySets != null ) {
+                for ( PolicySet policySet : domainPolicySets ) {
+                    domainPolicySetMap.put(policySet.getName(), policySet);
+                } 
+            }
+            
+            for ( Object object : scaDefnsSink ) {
+                if ( object instanceof Definitions ) {
+                    for ( PolicySet policySet : ((Definitions)object).getPolicySets() ) {
+                        domainPolicySetMap.put( policySet.getName(), policySet);
+                    }
+                }
+            }
+            domainPolicySets =  domainPolicySetMap.values();
+            //scaDefnsSink.clear();
+            scaDefnsCount = scaDefnsSink.size();
+        }
+    }
+    */
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeModelResolver.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeModelResolver.java
new file mode 100644
index 0000000000..62ed95cb01
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeModelResolver.java
@@ -0,0 +1,83 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.xml.namespace.QName;
+
+import org.apache.tuscany.sca.assembly.Composite;
+import org.apache.tuscany.sca.contribution.Contribution;
+import org.apache.tuscany.sca.contribution.Import;
+import org.apache.tuscany.sca.contribution.namespace.NamespaceImport;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+
+/**
+ * A Model Resolver for Composite models.
+ *
+ * @version $Rev$ $Date$
+ */
+public class CompositeModelResolver implements ModelResolver {
+
+    private Contribution contribution;
+    private Map<QName, Composite> map = new HashMap<QName, Composite>();
+    
+    public CompositeModelResolver(Contribution contribution, FactoryExtensionPoint modelFactories) {
+        this.contribution = contribution;
+    }
+
+    public void addModel(Object resolved) {
+        Composite composite = (Composite)resolved;
+        map.put(composite.getName(), composite);
+    }
+    
+    public Object removeModel(Object resolved) {
+        return map.remove(((Composite)resolved).getName());
+    }
+    
+    public <T> T resolveModel(Class<T> modelClass, T unresolved) {
+        
+        // Lookup a definition for the given namespace
+        QName qname = ((Composite)unresolved).getName();
+        Composite resolved = (Composite) map.get(qname);
+        if (resolved != null) {
+            return modelClass.cast(resolved);
+        }
+        
+        // No definition found, delegate the resolution to the imports
+        for (Import import_ : this.contribution.getImports()) {
+            if (import_ instanceof NamespaceImport) {
+                NamespaceImport namespaceImport = (NamespaceImport)import_;
+                if (namespaceImport.getNamespace().equals(qname.getNamespaceURI())) {
+                    
+                    // Delegate the resolution to the import resolver
+                    resolved = namespaceImport.getModelResolver().resolveModel(Composite.class, (Composite)unresolved);
+                    if (!resolved.isUnresolved()) {
+                        return modelClass.cast(resolved);
+                    }
+                }
+            }
+        }
+        return (T)unresolved;
+    }
+    
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeProcessor.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeProcessor.java
new file mode 100644
index 0000000000..7a2eba494f
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeProcessor.java
@@ -0,0 +1,1047 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import static javax.xml.stream.XMLStreamConstants.END_ELEMENT;
+import static javax.xml.stream.XMLStreamConstants.START_ELEMENT;
+import static org.apache.tuscany.sca.assembly.xml.Constants.AUTOWIRE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.CALLBACK;
+import static org.apache.tuscany.sca.assembly.xml.Constants.CALLBACK_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.COMPONENT;
+import static org.apache.tuscany.sca.assembly.xml.Constants.COMPONENT_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.COMPOSITE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.COMPOSITE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.ELEMENT;
+import static org.apache.tuscany.sca.assembly.xml.Constants.FILE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.IMPLEMENTATION_COMPOSITE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.IMPLEMENTATION_COMPOSITE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.INCLUDE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.INCLUDE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.LOCAL;
+import static org.apache.tuscany.sca.assembly.xml.Constants.MANY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.MUST_SUPPLY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.NAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.NONOVERRIDABLE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.PROMOTE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.PROPERTY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.PROPERTY_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.REFERENCE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.REFERENCE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.REPLACE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.SCA11_NS;
+import static org.apache.tuscany.sca.assembly.xml.Constants.SERVICE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.SERVICE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.SOURCE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.TARGET;
+import static org.apache.tuscany.sca.assembly.xml.Constants.TARGET_NAMESPACE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.TYPE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.URI;
+import static org.apache.tuscany.sca.assembly.xml.Constants.WIRE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.WIRED_BY_IMPL;
+import static org.apache.tuscany.sca.assembly.xml.Constants.WIRE_QNAME;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.StringTokenizer;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamConstants;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+import javax.xml.xpath.XPath;
+import javax.xml.xpath.XPathExpressionException;
+import javax.xml.xpath.XPathFactory;
+
+import org.apache.tuscany.sca.assembly.Binding;
+import org.apache.tuscany.sca.assembly.Callback;
+import org.apache.tuscany.sca.assembly.Component;
+import org.apache.tuscany.sca.assembly.ComponentProperty;
+import org.apache.tuscany.sca.assembly.ComponentReference;
+import org.apache.tuscany.sca.assembly.ComponentService;
+import org.apache.tuscany.sca.assembly.Composite;
+import org.apache.tuscany.sca.assembly.CompositeReference;
+import org.apache.tuscany.sca.assembly.CompositeService;
+import org.apache.tuscany.sca.assembly.ConstrainingType;
+import org.apache.tuscany.sca.assembly.Contract;
+import org.apache.tuscany.sca.assembly.Implementation;
+import org.apache.tuscany.sca.assembly.Property;
+import org.apache.tuscany.sca.assembly.Reference;
+import org.apache.tuscany.sca.assembly.Service;
+import org.apache.tuscany.sca.assembly.Wire;
+import org.apache.tuscany.sca.contribution.Artifact;
+import org.apache.tuscany.sca.contribution.ContributionFactory;
+import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
+import org.apache.tuscany.sca.contribution.processor.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.processor.ContributionWriteException;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.StAXAttributeProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.contribution.resolver.ResolverExtension;
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.core.UtilityExtensionPoint;
+import org.apache.tuscany.sca.interfacedef.InterfaceContract;
+import org.apache.tuscany.sca.monitor.Monitor;
+import org.apache.tuscany.sca.monitor.MonitorFactory;
+import org.apache.tuscany.sca.policy.ExtensionType;
+import org.apache.tuscany.sca.policy.PolicyFactory;
+import org.apache.tuscany.sca.policy.PolicySubject;
+import org.w3c.dom.Document;
+
+/**
+ * A composite processor. 
+ * 
+ * @version $Rev$ $Date$
+ */
+public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArtifactProcessor<Composite> {
+    private XPathFactory xPathFactory;
+    private PolicyFactory intentAttachPointTypeFactory;
+    private StAXAttributeProcessor<Object> extensionAttributeProcessor;
+    private ContributionFactory contributionFactory;
+
+    
+    /**
+     * Construct a new composite processor
+     * 
+     * @param extensionPoints
+     * @param extensionProcessor
+     */
+    public CompositeProcessor(ExtensionPointRegistry extensionPoints,
+			StAXArtifactProcessor extensionProcessor,
+			StAXAttributeProcessor extensionAttributeProcessor, 
+			Monitor monitor) {
+        
+    	this(modelFactories(extensionPoints), 
+    		extensionProcessor, 
+    		extensionAttributeProcessor, 
+    		monitor(extensionPoints));
+        
+    	this.extensionAttributeProcessor = extensionAttributeProcessor;
+    }
+    
+    /**
+     * Constructs a new composite processor
+     * 
+     * @param modelFactories
+     * @param extensionProcessor
+     * @param monitor
+     */
+    private CompositeProcessor(FactoryExtensionPoint modelFactories,
+             StAXArtifactProcessor extensionProcessor,
+             StAXAttributeProcessor extensionAttributeProcessor,
+             Monitor monitor) {
+        
+    	super(modelFactories, extensionProcessor, monitor);
+        this.intentAttachPointTypeFactory = modelFactories.getFactory(PolicyFactory.class);
+        this.xPathFactory = modelFactories.getFactory(XPathFactory.class);
+        this.contributionFactory = modelFactories.getFactory(ContributionFactory.class);
+        this.extensionAttributeProcessor = extensionAttributeProcessor;
+        
+    }
+    
+    public Composite read(XMLStreamReader reader) throws ContributionReadException {
+        Composite composite = null;
+        Composite include = null;
+        Component component = null;
+        Property property = null;
+        ComponentService componentService = null;
+        ComponentReference componentReference = null;
+        ComponentProperty componentProperty = null;
+        CompositeService compositeService = null;
+        CompositeReference compositeReference = null;
+        Contract contract = null;
+        Wire wire = null;
+        Callback callback = null;
+        QName name = null;
+
+        try {
+            // Read the composite document
+            while (reader.hasNext()) {
+                int event = reader.getEventType();
+                switch (event) {
+                    case START_ELEMENT:
+                        name = reader.getName();
+    
+                        if (COMPOSITE_QNAME.equals(name)) {
+    
+                            // Read a <composite>
+                            composite = assemblyFactory.createComposite();
+                            composite.setSpecVersion(Constants.SCA11_NS);
+                            
+                            composite.setName(new QName(getString(reader, TARGET_NAMESPACE), getString(reader, NAME)));
+    
+                            if(!isSet(reader, TARGET_NAMESPACE)){
+                                // spec says that a composite must have a namespace
+                                warning("NoCompositeNamespace", composite, composite.getName().toString());   
+                            }
+                            
+                            if(isSet(reader, AUTOWIRE)) {
+                                composite.setAutowire(getBoolean(reader, AUTOWIRE));
+                            }
+                            
+                            //handle extension attributes
+                            this.readExtendedAttributes(reader, name, composite, extensionAttributeProcessor);
+    
+                            composite.setLocal(getBoolean(reader, LOCAL));
+                            composite.setConstrainingType(readConstrainingType(reader));
+                            policyProcessor.readPolicies(composite, reader);
+    
+                        } else if (INCLUDE_QNAME.equals(name)) {
+    
+                            // Read an <include>
+                            include = assemblyFactory.createComposite();
+                            include.setName(getQName(reader, NAME));
+                            include.setURI(getString(reader, URI));
+                            include.setUnresolved(true);
+                            composite.getIncludes().add(include);
+    
+                        } else if (SERVICE_QNAME.equals(name)) {
+                            if (component != null) {
+    
+                                // Read a <component><service>
+                                componentService = assemblyFactory.createComponentService();
+                                contract = componentService;
+                                componentService.setName(getString(reader, NAME));
+                                
+                                //handle extension attributes
+                                this.readExtendedAttributes(reader, name, componentService, extensionAttributeProcessor);
+    
+                                component.getServices().add(componentService);
+                                policyProcessor.readPolicies(contract, reader);
+                            } else {
+    
+                                // Read a <composite><service>
+                                compositeService = assemblyFactory.createCompositeService();
+                                contract = compositeService;
+                                compositeService.setName(getString(reader, NAME));
+    
+                                String promoted = getString(reader, PROMOTE);
+                                if (promoted != null) {
+                                    String promotedComponentName;
+                                    String promotedServiceName;
+                                    int s = promoted.indexOf('/');
+                                    if (s == -1) {
+                                        promotedComponentName = promoted;
+                                        promotedServiceName = null;
+                                    } else {
+                                        promotedComponentName = promoted.substring(0, s);
+                                        promotedServiceName = promoted.substring(s + 1);
+                                    }
+        
+                                    Component promotedComponent = assemblyFactory.createComponent();
+                                    promotedComponent.setUnresolved(true);
+                                    promotedComponent.setName(promotedComponentName);
+                                    compositeService.setPromotedComponent(promotedComponent);
+        
+                                    ComponentService promotedService = assemblyFactory.createComponentService();
+                                    promotedService.setUnresolved(true);
+                                    promotedService.setName(promotedServiceName);
+                                    compositeService.setPromotedService(promotedService);
+                                }
+    
+                                //handle extension attributes
+                                this.readExtendedAttributes(reader, name, compositeService, extensionAttributeProcessor);
+    
+                                composite.getServices().add(compositeService);
+                                policyProcessor.readPolicies(contract, reader);
+                            }
+    
+                        } else if (REFERENCE_QNAME.equals(name)) {
+                            if (component != null) {
+                                // Read a <component><reference>
+                                componentReference = assemblyFactory.createComponentReference();
+                                contract = componentReference;
+                                componentReference.setName(getString(reader, NAME));
+                                readMultiplicity(componentReference, reader);
+                                if (isSet(reader, AUTOWIRE)) {
+                                    componentReference.setAutowire(getBoolean(reader, AUTOWIRE));
+                                }
+                                // Read @nonOverridable
+                                String nonOverridable = reader.getAttributeValue(null, NONOVERRIDABLE);
+                                if (nonOverridable != null) {
+                                    componentReference.setNonOverridable(Boolean.parseBoolean(nonOverridable));
+                                }
+                                readTargets(componentReference, reader);
+                                componentReference.setWiredByImpl(getBoolean(reader, WIRED_BY_IMPL));
+                                
+                                //handle extension attributes
+                                this.readExtendedAttributes(reader, name, componentReference, extensionAttributeProcessor);
+    
+                                component.getReferences().add(componentReference);
+                                policyProcessor.readPolicies(contract, reader);
+                            } else {
+                                // Read a <composite><reference>
+                                compositeReference = assemblyFactory.createCompositeReference();
+                                contract = compositeReference;
+                                compositeReference.setName(getString(reader, NAME));
+                                readMultiplicity(compositeReference, reader);
+                                readTargets(compositeReference, reader);
+                                String promote = reader.getAttributeValue(null, Constants.PROMOTE);
+                                if (promote != null) {
+                                    for (StringTokenizer tokens = new StringTokenizer(promote); tokens.hasMoreTokens();) {
+                                        String refName = tokens.nextToken();
+                                        Component promotedComponent = assemblyFactory.createComponent();
+                                        int index = refName.indexOf('/');
+                                        if (index == -1) {
+                                            error("Invalid reference name", compositeReference, refName);
+                                        }
+                                        String promotedComponentName = refName.substring(0, index); 
+                                        promotedComponent.setName(promotedComponentName);
+                                        promotedComponent.setUnresolved(true);
+                                        compositeReference.getPromotedComponents().add(promotedComponent);
+                                        ComponentReference promotedReference =
+                                            assemblyFactory.createComponentReference();
+                                        promotedReference.setUnresolved(true);
+                                        promotedReference.setName(refName);
+                                        compositeReference.getPromotedReferences().add(promotedReference);
+                                    }
+                                }
+                                compositeReference.setWiredByImpl(getBoolean(reader, WIRED_BY_IMPL));
+                                
+                                //handle extension attributes
+                                this.readExtendedAttributes(reader, name, compositeReference, extensionAttributeProcessor);
+    
+                                composite.getReferences().add(compositeReference);                            
+                                policyProcessor.readPolicies(contract, reader);
+                            }
+    
+                        } else if (PROPERTY_QNAME.equals(name)) {
+                            if (component != null) {
+    
+                                // Read a <component><property>
+                                componentProperty = assemblyFactory.createComponentProperty();
+                                property = componentProperty;
+                                String source = getString(reader, SOURCE);
+                                if(source!=null) {
+                                    source = source.trim();
+                                }
+                                componentProperty.setSource(source);
+                                if (source != null) {
+                                    // $<name>/...
+                                    if (source.charAt(0) == '$') {
+                                        int index = source.indexOf('/');
+                                        if (index == -1) {
+                                            // Tolerating $prop
+                                            source = source + "/";
+                                            index = source.length() - 1;
+                                        }
+                                        source = source.substring(index + 1);
+                                        if ("".equals(source)) {
+                                            source = ".";
+                                        }
+                                    }
+                                    XPath xpath = xPathFactory.newXPath();
+                                    xpath.setNamespaceContext(reader.getNamespaceContext());
+                                    try {
+                                        componentProperty.setSourceXPathExpression(xpath.compile(source));
+                                    } catch (XPathExpressionException e) {
+                                    	ContributionReadException ce = new ContributionReadException(e);
+                                    	error("ContributionReadException", xpath, ce);
+                                        //throw ce;
+                                    }
+                                }
+                                componentProperty.setFile(getString(reader, FILE));
+                                
+                                //handle extension attributes
+                                this.readExtendedAttributes(reader, name, componentProperty, extensionAttributeProcessor);
+    
+                                policyProcessor.readPolicies(property, reader);
+                                readAbstractProperty(componentProperty, reader);
+                                
+                                // Read the property value
+                                Document value = readPropertyValue(property.getXSDElement(), property.getXSDType(), reader);
+                                property.setValue(value);
+                                
+                                component.getProperties().add(componentProperty);
+                            } else {
+    
+                                // Read a <composite><property>
+                                property = assemblyFactory.createProperty();
+                                policyProcessor.readPolicies(property, reader);
+                                readAbstractProperty(property, reader);
+                                
+                                // Read the property value
+                                Document value = readPropertyValue(property.getXSDElement(), property.getXSDType(), reader);
+                                property.setValue(value);
+                                
+                                composite.getProperties().add(property);
+                            }
+                            
+                            // TUSCANY-1949
+                            // If the property doesn't have a value, the END_ELEMENT event is read by the readPropertyValue
+                            if (reader.getEventType() == END_ELEMENT && PROPERTY_QNAME.equals(reader.getName())) {
+                                property = null;
+                                componentProperty = null;
+                            }
+    
+                        } else if (COMPONENT_QNAME.equals(name)) {
+    
+                            // Read a <component>
+                            component = assemblyFactory.createComponent();
+                            component.setName(getString(reader, NAME));
+                            if (isSet(reader, AUTOWIRE)) {
+                                component.setAutowire(getBoolean(reader, AUTOWIRE));
+                            }
+                            if (isSet(reader, URI)) {
+                                component.setURI(getString(reader, URI));
+                            }
+                            
+                            //handle extension attributes
+                           this.readExtendedAttributes(reader, name, component, extensionAttributeProcessor);
+                            
+                            component.setConstrainingType(readConstrainingType(reader));
+                            composite.getComponents().add(component);
+                            policyProcessor.readPolicies(component, reader);
+    
+                        } else if (WIRE_QNAME.equals(name)) {
+    
+                            // Read a <wire>
+                            wire = assemblyFactory.createWire();
+                            ComponentReference source = assemblyFactory.createComponentReference();
+                            source.setUnresolved(true);
+                            source.setName(getString(reader, SOURCE));
+                            wire.setSource(source);
+    
+                            ComponentService target = assemblyFactory.createComponentService();
+                            target.setUnresolved(true);
+                            target.setName(getString(reader, TARGET));
+                            wire.setTarget(target);
+                            
+                            // Read @replace
+                            String replace = reader.getAttributeValue(null, REPLACE);
+                            if (replace != null) {
+                                wire.setReplace(Boolean.parseBoolean(replace));
+                            }
+    
+                            //handle extension attributes
+                            this.readExtendedAttributes(reader, name, wire, extensionAttributeProcessor);
+    
+                            composite.getWires().add(wire);
+                            policyProcessor.readPolicies(wire, reader);
+    
+                        } else if (CALLBACK_QNAME.equals(name)) {
+    
+                            // Read a <callback>
+                            callback = assemblyFactory.createCallback();
+                            contract.setCallback(callback);
+                            
+                            //handle extension attributes
+                            this.readExtendedAttributes(reader, name, callback, extensionAttributeProcessor);
+                            
+                            policyProcessor.readPolicies(callback, reader);
+    
+                        } else if (IMPLEMENTATION_COMPOSITE_QNAME.equals(name)) {
+    
+                            // Read an implementation.composite
+                            Composite implementation = assemblyFactory.createComposite();
+                            implementation.setName(getQName(reader, NAME));
+                            implementation.setUnresolved(true);
+                            
+                            //handle extension attributes
+                            this.readExtendedAttributes(reader, name, implementation, extensionAttributeProcessor);
+    
+                            component.setImplementation(implementation);
+                            policyProcessor.readPolicies(implementation, reader);
+                        } else {
+    
+                            // Read an extension element
+                            Object extension = extensionProcessor.read(reader);
+                            if (extension != null) {
+                                if (extension instanceof InterfaceContract) {
+    
+                                    // <service><interface> and
+                                    // <reference><interface>
+                                    if (contract != null) {
+                                        contract.setInterfaceContract((InterfaceContract)extension);
+                                    } else {
+                                        if (name.getNamespaceURI().equals(SCA11_NS)) {
+                                        	error("UnexpectedInterfaceElement", extension);
+                                            //throw new ContributionReadException("Unexpected <interface> element found. It should appear inside a <service> or <reference> element");
+                                        } else {
+                                            composite.getExtensions().add(extension);
+                                        }
+                                    }
+                                } else if (extension instanceof Binding) {
+                                    if ( extension instanceof PolicySubject ) {
+                                        ExtensionType bindingType = intentAttachPointTypeFactory.createBindingType();
+                                        bindingType.setType(name);
+                                        bindingType.setUnresolved(true);
+                                        ((PolicySubject)extension).setType(bindingType);
+                                    }
+                                    // <service><binding> and
+                                    // <reference><binding>
+                                    if (callback != null) {
+                                        callback.getBindings().add((Binding)extension);
+                                    } else {
+                                        if (contract != null) {
+                                            contract.getBindings().add((Binding)extension);
+                                        } else {
+                                            if (name.getNamespaceURI().equals(SCA11_NS)) {
+                                            	error("UnexpectedBindingElement", extension);
+                                                //throw new ContributionReadException("Unexpected <binding> element found. It should appear inside a <service> or <reference> element");
+                                            } else {
+                                                composite.getExtensions().add(extension);
+                                            }
+                                        }
+                                    }
+    
+                                } else if (extension instanceof Implementation) {
+                                    if ( extension instanceof PolicySubject ) {
+                                        ExtensionType implType = intentAttachPointTypeFactory.createImplementationType();
+                                        implType.setType(name);
+                                        implType.setUnresolved(true);
+                                        ((PolicySubject)extension).setType(implType);
+                                    }
+                                    // <component><implementation>
+                                    if (component != null) {
+                                        component.setImplementation((Implementation)extension);
+                                    } else {
+                                        if (name.getNamespaceURI().equals(SCA11_NS)) {
+                                        	error("UnexpectedImplementationElement", extension);
+                                            //throw new ContributionReadException("Unexpected <implementation> element found. It should appear inside a <component> element");
+                                        } else {
+                                            composite.getExtensions().add(extension);
+                                        }
+                                    }
+                                } else {
+    
+                                    // Add the extension element to the current
+                                    // element
+                                    if (callback != null) {
+                                        callback.getExtensions().add(extension);
+                                    } else if (contract != null) {
+                                        contract.getExtensions().add(extension);
+                                    } else if (property != null) {
+                                        property.getExtensions().add(extension);
+                                    } else if (component != null) {
+                                        component.getExtensions().add(extension);
+                                    } else {
+                                        composite.getExtensions().add(extension);
+                                    }
+                                }
+                            }
+                        }
+                        break;
+    
+                    case XMLStreamConstants.CHARACTERS:
+                        break;
+    
+                    case END_ELEMENT:
+                        name = reader.getName();
+    
+                        // Clear current state when reading reaching end element
+                        if (SERVICE_QNAME.equals(name)) {
+                            componentService = null;
+                            compositeService = null;
+                            contract = null;
+                        } else if (INCLUDE_QNAME.equals(name)) {
+                            include = null;
+                        } else if (REFERENCE_QNAME.equals(name)) {
+                            componentReference = null;
+                            compositeReference = null;
+                            contract = null;
+                        } else if (PROPERTY_QNAME.equals(name)) {
+                            componentProperty = null;
+                            property = null;
+                        } else if (COMPONENT_QNAME.equals(name)) {
+                            component = null;
+                        } else if (WIRE_QNAME.equals(name)) {
+                            wire = null;
+                        } else if (CALLBACK_QNAME.equals(name)) {
+                            callback = null;
+                        }
+                        break;
+                }
+    
+                // Read the next element
+                if (reader.hasNext()) {
+                    reader.next();
+                }
+            }
+        }
+        catch (XMLStreamException e) {
+            ContributionReadException ex = new ContributionReadException(e);
+            error("XMLStreamException", reader, ex);
+        }
+        
+        return composite;
+    }
+
+    public void write(Composite composite, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {
+
+        // Write <composite> element
+        writeStartDocument(writer,
+                           COMPOSITE,
+                           writeConstrainingType(composite),
+                           new XAttr(TARGET_NAMESPACE, composite.getName().getNamespaceURI()),
+                           new XAttr(NAME, composite.getName().getLocalPart()),
+                           new XAttr(LOCAL, composite.isLocal() ? Boolean.TRUE : null),
+                           new XAttr(AUTOWIRE, composite.getAutowire()),
+                           policyProcessor.writePolicies(composite));
+        
+        //write extended attributes
+        this.writeExtendedAttributes(writer, composite, extensionAttributeProcessor);
+
+        // Write <include> elements
+        for (Composite include : composite.getIncludes()) {
+            String uri = include.isUnresolved()? include.getURI() : null;
+            writeStart(writer,
+                       INCLUDE,
+                       new XAttr(NAME, include.getName()),
+                       new XAttr(URI, uri));
+
+            //write extended attributes
+            this.writeExtendedAttributes(writer, include, extensionAttributeProcessor);
+            
+            writeEnd(writer);
+        }
+
+        // Write <service> elements
+        for (Service service : composite.getServices()) {
+            CompositeService compositeService = (CompositeService)service;
+            Component promotedComponent = compositeService.getPromotedComponent();
+            ComponentService promotedService = compositeService.getPromotedService();
+            String promote;
+            if (promotedService != null) {
+                if (promotedService.getName() != null) {
+                    promote = promotedComponent.getName() + '/' + promotedService.getName();
+                } else {
+                    promote = promotedComponent.getName();
+                }
+            } else {
+                promote = null;
+            }
+            writeStart(writer, SERVICE, new XAttr(NAME, service.getName()), new XAttr(PROMOTE, promote),
+                       policyProcessor.writePolicies(service));
+            
+            //write extended attributes
+            this.writeExtendedAttributes(writer, service, extensionAttributeProcessor);
+
+            
+            // Write service interface
+            extensionProcessor.write(service.getInterfaceContract(), writer);
+
+            // Write bindings
+            for (Binding binding : service.getBindings()) {
+                extensionProcessor.write(binding, writer);
+            }
+
+            // Write <callback> element
+            if (service.getCallback() != null) {
+                Callback callback = service.getCallback();
+                writeStart(writer, CALLBACK,
+                           policyProcessor.writePolicies(callback));
+            
+                //write extended attributes
+                this.writeExtendedAttributes(writer, callback, extensionAttributeProcessor);
+
+                // Write callback bindings
+                for (Binding binding : callback.getBindings()) {
+                    extensionProcessor.write(binding, writer);
+                }
+                
+                // Write extensions 
+                for (Object extension : callback.getExtensions()) {
+                    extensionProcessor.write(extension, writer);
+                }
+            
+                writeEnd(writer);
+            }
+
+            // Write extensions
+            for (Object extension : service.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+            
+            writeEnd(writer);
+        }
+
+        // Write <component> elements
+        for (Component component : composite.getComponents()) {
+            writeStart(writer, COMPONENT, new XAttr(NAME, component.getName()),
+                       new XAttr(URI, component.getURI()),
+                       new XAttr(AUTOWIRE, component.getAutowire()),
+                       policyProcessor.writePolicies(component));
+            
+            //write extended attributes
+            this.writeExtendedAttributes(writer, component, extensionAttributeProcessor);
+            
+            // Write the component implementation
+            Implementation implementation = component.getImplementation();
+            if (implementation instanceof Composite) {
+                writeStart(writer, IMPLEMENTATION_COMPOSITE, new XAttr(NAME, ((Composite)implementation).getName()));
+                
+                //write extended attributes
+                this.writeExtendedAttributes(writer, (Composite)implementation, extensionAttributeProcessor);
+
+                writeEnd(writer);
+            } else {
+                extensionProcessor.write(component.getImplementation(), writer);
+            }
+            
+            for (Object extension : component.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }            
+            
+            // Write <service> elements
+            for (ComponentService service : component.getServices()) {
+                writeStart(writer, SERVICE, new XAttr(NAME, service.getName()),
+                           policyProcessor.writePolicies(service));
+
+                //write extended attributes
+                this.writeExtendedAttributes(writer, service, extensionAttributeProcessor);
+
+                // Write service interface
+                extensionProcessor.write(service.getInterfaceContract(), writer);
+                
+                // Write bindings
+                for (Binding binding : service.getBindings()) {
+                    extensionProcessor.write(binding, writer);
+                }
+                
+                // Write <callback> element
+                if (service.getCallback() != null) {
+                    Callback callback = service.getCallback();
+                    writeStart(writer, CALLBACK, policyProcessor.writePolicies(callback));
+
+                    //write extended attributes
+                    this.writeExtendedAttributes(writer, callback, extensionAttributeProcessor);
+
+                    // Write bindings
+                    for (Binding binding : callback.getBindings()) {
+                        extensionProcessor.write(binding, writer);
+                    }
+                    
+                    // Write extensions 
+                    for (Object extension : callback.getExtensions()) {
+                        extensionProcessor.write(extension, writer);
+                    }
+                
+                    writeEnd(writer);
+                }
+                
+                // Write extensions
+                for (Object extension : service.getExtensions()) {
+                    extensionProcessor.write(extension, writer);
+                }
+                
+                writeEnd(writer);
+            }
+            
+            // Write <reference> elements
+            for (ComponentReference reference : component.getReferences()) {
+                writeStart(writer, 
+                           REFERENCE, 
+                           new XAttr(NAME, reference.getName()), 
+                           new XAttr(AUTOWIRE, reference.getAutowire()), 
+                           (reference.isNonOverridable() ? new XAttr(NONOVERRIDABLE, true) : null), 
+                           writeMultiplicity(reference), 
+                           writeTargets(reference), 
+                           policyProcessor.writePolicies(reference));
+
+                //write extended attributes
+                this.writeExtendedAttributes(writer, reference, extensionAttributeProcessor);
+
+                // Write reference interface
+                extensionProcessor.write(reference.getInterfaceContract(), writer);
+
+                // Write bindings
+                for (Binding binding : reference.getBindings()) {
+                    extensionProcessor.write(binding, writer);
+                }
+                
+                // Write callback
+                if (reference.getCallback() != null) {
+                    Callback callback = reference.getCallback();
+                    writeStart(writer, CALLBACK, policyProcessor.writePolicies(callback));
+                
+                    //write extended attributes
+                    this.writeExtendedAttributes(writer, callback, extensionAttributeProcessor);
+
+                    // Write callback bindings
+                    for (Binding binding : callback.getBindings()) {
+                        extensionProcessor.write(binding, writer);
+                    }
+                    
+                    // Write extensions
+                    for (Object extensions : callback.getExtensions()) {
+                        extensionProcessor.write(extensions, writer);
+                    }
+                
+                    writeEnd(writer);
+                }
+                
+                // Write extensions
+                for (Object extensions : reference.getExtensions()) {
+                    extensionProcessor.write(extensions, writer);
+                }
+                
+                writeEnd(writer);
+            }
+            
+            // Write <property> elements
+            for (ComponentProperty property : component.getProperties()) {
+                writeStart(writer,
+                           PROPERTY,
+                           new XAttr(NAME, property.getName()),
+                           new XAttr(MUST_SUPPLY, property.isMustSupply()),
+                           new XAttr(MANY, property.isMany()),
+                           new XAttr(TYPE, property.getXSDType()),
+                           new XAttr(ELEMENT, property.getXSDElement()),
+                           new XAttr(SOURCE, property.getSource()),
+                           new XAttr(FILE, property.getFile()),
+                           policyProcessor.writePolicies(property));
+
+                //write extended attributes
+                this.writeExtendedAttributes(writer, property, extensionAttributeProcessor);
+
+                // Write property value
+                writePropertyValue(property.getValue(), property.getXSDElement(), property.getXSDType(), writer);
+
+                // Write extensions
+                for (Object extension : property.getExtensions()) {
+                    extensionProcessor.write(extension, writer);
+                }
+
+                writeEnd(writer);
+            }
+ 
+            writeEnd(writer);
+        }
+
+        // Write <reference> elements
+        for (Reference reference : composite.getReferences()) {
+            CompositeReference compositeReference = (CompositeReference)reference;
+
+            // Write list of promoted references
+            List<String> promote = new ArrayList<String>();
+            for (ComponentReference promoted: compositeReference.getPromotedReferences()) {
+                promote.add(promoted.getName());
+            }
+            
+            // Write <reference> element
+            writeStart(writer, REFERENCE, new XAttr(NAME, reference.getName()),
+                       new XAttr(PROMOTE, promote),
+                       writeMultiplicity(reference),
+                       policyProcessor.writePolicies(reference));
+
+            //write extended attributes
+            this.writeExtendedAttributes(writer, reference, extensionAttributeProcessor);
+
+            // Write reference interface
+            extensionProcessor.write(reference.getInterfaceContract(), writer);
+            
+            // Write bindings
+            for (Binding binding : reference.getBindings()) {
+                extensionProcessor.write(binding, writer);
+            }
+            
+            // Write <callback> element
+            if (reference.getCallback() != null) {
+                Callback callback = reference.getCallback();
+                writeStart(writer, CALLBACK);
+            
+                //write extended attributes
+                this.writeExtendedAttributes(writer, callback, extensionAttributeProcessor);
+
+                // Write callback bindings
+                for (Binding binding : callback.getBindings()) {
+                    extensionProcessor.write(binding, writer);
+                }
+                
+                // Write extensions
+                for (Object extension : callback.getExtensions()) {
+                    extensionProcessor.write(extension, writer);
+                }
+            
+                writeEnd(writer);
+            }
+            
+            // Write extensions
+            for (Object extension : reference.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+            
+            writeEnd(writer);
+        }
+
+        // Write <property> elements
+        for (Property property : composite.getProperties()) {
+            writeStart(writer,
+                       PROPERTY,
+                       new XAttr(NAME, property.getName()),
+                       new XAttr(MUST_SUPPLY, property.isMustSupply()),
+                       new XAttr(MANY, property.isMany()),
+                       new XAttr(TYPE, property.getXSDType()),
+                       new XAttr(ELEMENT, property.getXSDElement()),
+                       policyProcessor.writePolicies(property));
+
+            //write extended attributes
+            this.writeExtendedAttributes(writer, property, extensionAttributeProcessor);
+
+            // Write property value
+            writePropertyValue(property.getValue(), property.getXSDElement(), property.getXSDType(), writer);
+
+            // Write extensions
+            for (Object extension : property.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+
+            writeEnd(writer);
+        }
+
+        // Write <wire> elements
+        for (Wire wire : composite.getWires()) {
+            writeStart(writer, WIRE, new XAttr(SOURCE, wire.getSource().getName()), new XAttr(TARGET, wire.getTarget()
+                .getName()), wire.isReplace() ? new XAttr(Constants.REPLACE, true) : null);
+            
+            //write extended attributes
+            this.writeExtendedAttributes(writer, wire, extensionAttributeProcessor);
+
+            // Write extensions
+            for (Object extension : wire.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+            writeEnd(writer);
+        }
+
+        for (Object extension : composite.getExtensions()) {
+        		extensionProcessor.write(extension, writer);
+        }
+        
+        writeEndDocument(writer);
+    }
+
+    public void resolve(Composite composite, ModelResolver resolver) throws ContributionResolveException {
+
+        // Resolve constraining type
+        ConstrainingType constrainingType = composite.getConstrainingType();
+        if (constrainingType != null) {
+            constrainingType = resolver.resolveModel(ConstrainingType.class, constrainingType);
+            composite.setConstrainingType(constrainingType);
+        }
+
+        // Resolve includes in the composite
+        for (int i = 0, n = composite.getIncludes().size(); i < n; i++) {
+            Composite include = composite.getIncludes().get(i);
+            if (include != null) {
+                include = resolver.resolveModel(Composite.class, include);
+                composite.getIncludes().set(i, include);
+            }
+        }
+
+        // Resolve extensions
+        for (Object extension : composite.getExtensions()) {
+            if (extension != null) {
+                extensionProcessor.resolve(extension, resolver);
+            }
+        }
+
+        //Resolve composite services and references
+        resolveContracts(composite, composite.getServices(), resolver);
+        resolveContracts(composite, composite.getReferences(), resolver);
+
+        // Resolve component implementations, services and references
+        for (Component component : composite.getComponents()) {
+            constrainingType = component.getConstrainingType();
+            if (constrainingType != null) {
+                constrainingType = resolver.resolveModel(ConstrainingType.class, constrainingType);
+                component.setConstrainingType(constrainingType);
+            }
+            
+            //resolve component services and references 
+            resolveContracts(component, component.getServices(), resolver);
+            resolveContracts(component, component.getReferences(), resolver);
+            
+            for (ComponentProperty componentProperty : component.getProperties()) {
+                if (componentProperty.getFile() != null) {
+                    Artifact artifact = contributionFactory.createArtifact();
+                    artifact.setURI(componentProperty.getFile());
+                    artifact = resolver.resolveModel(Artifact.class, artifact);
+                    if (artifact.getLocation() != null) {
+                        componentProperty.setFile(artifact.getLocation());
+                    }
+                }
+            }
+            
+            //resolve component implementation
+            Implementation implementation = component.getImplementation();
+            if (implementation != null) {
+                //now resolve the implementation so that even if there is a shared instance
+                //for this that is resolved, the specified intents and policysets are safe in the
+                //component and not lost
+                implementation = resolveImplementation(implementation, resolver);
+
+                component.setImplementation(implementation);
+            }
+
+            //add model resolver to component
+            if (component instanceof ResolverExtension) {
+                ((ResolverExtension)component).setModelResolver(resolver);
+            }
+        }
+
+        // Add model resolver to promoted components
+        for (Service service : composite.getServices()) {
+            CompositeService compositeService = (CompositeService)service;
+            Component promotedComponent = compositeService.getPromotedComponent();
+            if (promotedComponent instanceof ResolverExtension) {
+                ((ResolverExtension)promotedComponent).setModelResolver(resolver);
+            }
+        }
+    }
+    
+    public QName getArtifactType() {
+        return COMPOSITE_QNAME;
+    }
+
+    public Class<Composite> getModelType() {
+        return Composite.class;
+    }
+
+    /**
+     * Returns the model factory extension point to use.
+     * 
+     * @param extensionPoints
+     * @return
+     */
+    private static FactoryExtensionPoint modelFactories(ExtensionPointRegistry extensionPoints) {
+        return extensionPoints.getExtensionPoint(FactoryExtensionPoint.class);
+    }
+    
+    /**
+     * Returns the monitor to use.
+     * 
+     * @param extensionPoints
+     * @return
+     */
+    private static Monitor monitor(ExtensionPointRegistry extensionPoints) {
+        UtilityExtensionPoint utilities = extensionPoints.getExtensionPoint(UtilityExtensionPoint.class);
+        if (utilities != null) {
+            MonitorFactory monitorFactory = utilities.getUtility(MonitorFactory.class);
+            if (monitorFactory != null) {
+                return monitorFactory.createMonitor();
+            }
+        }
+        return null;
+    }
+    
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/Constants.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/Constants.java
new file mode 100644
index 0000000000..ce8b461a27
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/Constants.java
@@ -0,0 +1,101 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import javax.xml.namespace.QName;
+
+/**
+ * Constants used in SCA assembly XML files.
+ *
+ * @version $Rev$ $Date$
+ */
+public interface Constants {
+    String SCA11_NS = "http://docs.oasis-open.org/ns/opencsa/sca/200903";
+    String SCA11_TUSCANY_NS = "http://tuscany.apache.org/xmlns/sca/1.1";
+    
+    String COMPONENT_TYPE = "componentType";
+    QName COMPONENT_TYPE_QNAME = new QName(SCA11_NS, COMPONENT_TYPE);
+    
+    String SERVICE = "service";
+    QName SERVICE_QNAME = new QName(SCA11_NS, SERVICE);
+    
+    String REFERENCE = "reference";
+    QName REFERENCE_QNAME = new QName(SCA11_NS, REFERENCE);
+    
+    String PROPERTY = "property";
+    QName PROPERTY_QNAME = new QName(SCA11_NS, PROPERTY);
+    
+    String CONSTRAINING_TYPE = "constrainingType";
+    QName CONSTRAINING_TYPE_QNAME = new QName(SCA11_NS, CONSTRAINING_TYPE);
+    
+    String COMPOSITE = "composite";
+    QName COMPOSITE_QNAME = new QName(SCA11_NS, COMPOSITE);
+    
+    String INCLUDE = "include";
+    QName INCLUDE_QNAME = new QName(SCA11_NS, INCLUDE); 
+    
+    String COMPONENT = "component";
+    QName COMPONENT_QNAME = new QName(SCA11_NS, COMPONENT);
+    
+    String WIRE = "wire";
+    QName WIRE_QNAME = new QName(SCA11_NS, WIRE);
+
+    String OPERATION = "operation";
+    QName OPERATION_QNAME = new QName(SCA11_NS, OPERATION);
+    
+    String CALLBACK = "callback";
+    QName CALLBACK_QNAME = new QName(SCA11_NS, CALLBACK);
+
+    String IMPLEMENTATION_COMPOSITE = "implementation.composite";
+    QName IMPLEMENTATION_COMPOSITE_QNAME = new QName(SCA11_NS, IMPLEMENTATION_COMPOSITE);
+    
+    String IMPLEMENTATION = "implementation";
+    QName IMPLEMENTATION_QNAME = new QName(SCA11_NS, IMPLEMENTATION);
+    
+    String BINDING_SCA = "binding.sca";
+    QName BINDING_SCA_QNAME = new QName(Constants.SCA11_NS, BINDING_SCA);
+    
+    String NAME = "name";
+    String VALUE = "value";
+    QName VALUE_QNAME = new QName(SCA11_NS, VALUE);    
+    String TARGET_NAMESPACE = "targetNamespace";
+    String LOCAL = "local";
+    String AUTOWIRE = "autowire";
+    String NONOVERRIDABLE = "nonOverridable";
+    String REPLACE = "replace";
+    String REQUIRES = "requires";
+    String POLICY_SETS = "policySets"; 
+    String APPLICABLE_POLICY_SETS = "applicablePolicySets";
+    String PROMOTE = "promote";
+    String TARGET = "target";
+    String WIRED_BY_IMPL = "wiredByImpl";
+    String MULTIPLICITY = "multiplicity";
+    String TYPE = "type";
+    String ELEMENT = "element";
+    String MANY = "many";
+    String MUST_SUPPLY = "mustSupply";
+    String SOURCE = "source";
+    String FILE = "file";
+    String URI = "uri";
+    String ZERO_ONE = "0..1";
+    String ZERO_N = "0..n";
+    String ONE_ONE = "1..1";
+    String ONE_N = "1..n";
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ConstrainingTypeDocumentProcessor.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ConstrainingTypeDocumentProcessor.java
new file mode 100644
index 0000000000..401fa7123e
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ConstrainingTypeDocumentProcessor.java
@@ -0,0 +1,127 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URI;
+import java.net.URL;
+import java.net.URLConnection;
+
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+
+import org.apache.tuscany.sca.assembly.ConstrainingType;
+import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
+import org.apache.tuscany.sca.contribution.processor.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.URLArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.ValidatingXMLInputFactory;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.monitor.Monitor;
+
+/**
+ * A contrainingType content handler.
+ * 
+ * @version $Rev$ $Date$
+ */
+public class ConstrainingTypeDocumentProcessor extends BaseAssemblyProcessor implements URLArtifactProcessor<ConstrainingType> {
+    private XMLInputFactory inputFactory;
+
+    /**
+     * Constructs a new constrainingType processor.
+     * @param modelFactories
+     * @param staxProcessor
+     */
+    public ConstrainingTypeDocumentProcessor(FactoryExtensionPoint modelFactories,
+                                             StAXArtifactProcessor staxProcessor,
+                                             Monitor monitor) {
+        super(modelFactories, staxProcessor, monitor);
+        this.inputFactory = modelFactories.getFactory(ValidatingXMLInputFactory.class);
+    }
+    
+    public ConstrainingType read(URL contributionURL, URI uri, URL url) throws ContributionReadException {
+        InputStream urlStream = null;
+        try {
+            
+            // Create a stream reader
+            URLConnection connection = url.openConnection();
+            connection.setUseCaches(false);
+            urlStream = connection.getInputStream();
+            XMLStreamReader reader = inputFactory.createXMLStreamReader(url.toString(), urlStream);
+            reader.nextTag();
+            
+            // Read the constrainingType model 
+            ConstrainingType constrainingType = (ConstrainingType)extensionProcessor.read(reader);
+
+            // For debugging purposes, write it back to XML
+//            if (constrainingType != null) {
+//                try {
+//                    ByteArrayOutputStream bos = new ByteArrayOutputStream();
+//                    XMLOutputFactory outputFactory = XMLOutputFactory.newInstance();
+//                    outputFactory.setProperty(XMLOutputFactory.IS_REPAIRING_NAMESPACES, Boolean.TRUE);
+//                    extensionProcessor.write(constrainingType, outputFactory.createXMLStreamWriter(bos));
+//                    Document document = DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(new ByteArrayInputStream(bos.toByteArray()));
+//                    OutputFormat format = new OutputFormat();
+//                    format.setIndenting(true);
+//                    format.setIndent(2);
+//                    XMLSerializer serializer = new XMLSerializer(System.out, format);
+//                    serializer.serialize(document);
+//                } catch (Exception e) {
+//                    e.printStackTrace();
+//                }
+//            }
+            
+            return constrainingType;
+            
+        } catch (XMLStreamException e) {
+        	ContributionReadException ce = new ContributionReadException(e);
+        	error("ContributionReadException", inputFactory, ce);
+            throw ce;
+        } catch (IOException e) {
+        	ContributionReadException ce = new ContributionReadException(e);
+        	error("ContributionReadException", inputFactory, ce);
+            throw ce;
+        } finally {
+            try {
+                if (urlStream != null) {
+                    urlStream.close();
+                    urlStream = null;
+                }
+            } catch (IOException ioe) {
+                //ignore
+            }
+        }
+    }
+    
+    public void resolve(ConstrainingType constrainingType, ModelResolver resolver) throws ContributionResolveException {
+        extensionProcessor.resolve(constrainingType, resolver);
+    }
+    
+    public String getArtifactType() {
+        return ".constrainingType";
+    }
+    
+    public Class<ConstrainingType> getModelType() {
+        return ConstrainingType.class;
+    }
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ConstrainingTypeModelResolver.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ConstrainingTypeModelResolver.java
new file mode 100644
index 0000000000..d73ce5ab66
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ConstrainingTypeModelResolver.java
@@ -0,0 +1,83 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import java.util.HashMap;
+import java.util.Map;
+
+import javax.xml.namespace.QName;
+
+import org.apache.tuscany.sca.assembly.ConstrainingType;
+import org.apache.tuscany.sca.contribution.Contribution;
+import org.apache.tuscany.sca.contribution.Import;
+import org.apache.tuscany.sca.contribution.namespace.NamespaceImport;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+
+/**
+ * A Model Resolver for ConstrainingType models.
+ *
+ * @version $Rev$ $Date$
+ */
+public class ConstrainingTypeModelResolver implements ModelResolver {
+
+    private Contribution contribution;
+    private Map<QName, ConstrainingType> map = new HashMap<QName, ConstrainingType>();
+    
+    public ConstrainingTypeModelResolver(Contribution contribution, FactoryExtensionPoint modelFactories) {
+        this.contribution = contribution;
+    }
+
+    public void addModel(Object resolved) {
+        ConstrainingType composite = (ConstrainingType)resolved;
+        map.put(composite.getName(), composite);
+    }
+    
+    public Object removeModel(Object resolved) {
+        return map.remove(((ConstrainingType)resolved).getName());
+    }
+    
+    public <T> T resolveModel(Class<T> modelClass, T unresolved) {
+        
+        // Lookup a definition for the given namespace
+        QName qname = ((ConstrainingType)unresolved).getName();
+        ConstrainingType resolved = (ConstrainingType) map.get(qname);
+        if (resolved != null) {
+            return modelClass.cast(resolved);
+        }
+        
+        // No definition found, delegate the resolution to the imports
+        for (Import import_ : this.contribution.getImports()) {
+            if (import_ instanceof NamespaceImport) {
+                NamespaceImport namespaceImport = (NamespaceImport)import_;
+                if (namespaceImport.getNamespace().equals(qname.getNamespaceURI())) {
+                    
+                    // Delegate the resolution to the import resolver
+                    resolved = namespaceImport.getModelResolver().resolveModel(ConstrainingType.class, (ConstrainingType)unresolved);
+                    if (!resolved.isUnresolved()) {
+                        return modelClass.cast(resolved);
+                    }
+                }
+            }
+        }
+        return (T)unresolved;
+    }
+    
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ConstrainingTypeProcessor.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ConstrainingTypeProcessor.java
new file mode 100644
index 0000000000..34c4bc9909
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ConstrainingTypeProcessor.java
@@ -0,0 +1,273 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import static javax.xml.stream.XMLStreamConstants.END_ELEMENT;
+import static javax.xml.stream.XMLStreamConstants.START_ELEMENT;
+import static org.apache.tuscany.sca.assembly.xml.Constants.CONSTRAINING_TYPE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.CONSTRAINING_TYPE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.ELEMENT;
+import static org.apache.tuscany.sca.assembly.xml.Constants.MANY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.MUST_SUPPLY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.NAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.OPERATION_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.PROPERTY;
+import static org.apache.tuscany.sca.assembly.xml.Constants.PROPERTY_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.REFERENCE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.REFERENCE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.SERVICE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.SERVICE_QNAME;
+import static org.apache.tuscany.sca.assembly.xml.Constants.TARGET_NAMESPACE;
+import static org.apache.tuscany.sca.assembly.xml.Constants.TYPE;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+
+import org.apache.tuscany.sca.assembly.AbstractContract;
+import org.apache.tuscany.sca.assembly.AbstractProperty;
+import org.apache.tuscany.sca.assembly.AbstractReference;
+import org.apache.tuscany.sca.assembly.AbstractService;
+import org.apache.tuscany.sca.assembly.ConstrainingType;
+import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
+import org.apache.tuscany.sca.contribution.processor.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.processor.ContributionWriteException;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.interfacedef.InterfaceContract;
+import org.apache.tuscany.sca.interfacedef.Operation;
+import org.apache.tuscany.sca.interfacedef.impl.OperationImpl;
+import org.apache.tuscany.sca.monitor.Monitor;
+import org.w3c.dom.Document;
+
+/**
+ * A constrainingType processor.
+ * 
+ * @version $Rev$ $Date$
+ */
+public class ConstrainingTypeProcessor extends BaseAssemblyProcessor implements StAXArtifactProcessor<ConstrainingType> {
+
+    /**
+     * Constructs a new constrainingType processor.
+     * 
+     * @param modelFactories
+     * @param extensionProcessor
+     */
+    public ConstrainingTypeProcessor(FactoryExtensionPoint modelFactories,
+                                     StAXArtifactProcessor extensionProcessor,
+                                     Monitor monitor) {
+        super(modelFactories, extensionProcessor, monitor);
+    }
+    
+    public ConstrainingType read(XMLStreamReader reader) throws ContributionReadException {
+        ConstrainingType constrainingType = null;
+        AbstractService abstractService = null;
+        AbstractReference abstractReference = null;
+        AbstractProperty abstractProperty = null;
+        AbstractContract abstractContract = null;
+        QName name = null;
+        
+        try {
+            // Read the constrainingType document
+            while (reader.hasNext()) {
+                int event = reader.getEventType();
+                switch (event) {
+    
+                    case START_ELEMENT:
+                        name = reader.getName();
+                        
+                        // Read a <constrainingType>
+                        if (Constants.CONSTRAINING_TYPE_QNAME.equals(name)) {
+                            constrainingType = assemblyFactory.createConstrainingType();
+                            constrainingType.setName(new QName(getString(reader, TARGET_NAMESPACE), getString(reader, NAME)));
+                            policyProcessor.readPolicies(constrainingType, reader);
+    
+                        } else if (Constants.SERVICE_QNAME.equals(name)) {
+                            
+                            // Read a <service>
+                            abstractService = assemblyFactory.createAbstractService();
+                            abstractContract = abstractService;
+                            abstractService.setName(getString(reader, Constants.NAME));
+                            constrainingType.getServices().add(abstractService);
+                            policyProcessor.readPolicies(abstractService, reader);
+    
+                        } else if (Constants.REFERENCE_QNAME.equals(name)) {
+                            
+                            // Read a <reference>
+                            abstractReference = assemblyFactory.createAbstractReference();
+                            abstractContract = abstractReference;
+                            abstractReference.setName(getString(reader, Constants.NAME));
+                            readMultiplicity(abstractReference, reader);
+                            constrainingType.getReferences().add(abstractReference);
+                            policyProcessor.readPolicies(abstractReference, reader);
+    
+                        } else if (Constants.PROPERTY_QNAME.equals(name)) {
+                            
+                            // Read a <property>
+                            abstractProperty = assemblyFactory.createAbstractProperty();
+                            readAbstractProperty(abstractProperty, reader);
+                            
+                            // Read the property value
+                            Document value = readPropertyValue(abstractProperty.getXSDElement(), abstractProperty.getXSDType(), reader);
+                            abstractProperty.setValue(value);
+                            
+                            constrainingType.getProperties().add(abstractProperty);
+                            policyProcessor.readPolicies(abstractProperty, reader);
+                            
+                        } else if (OPERATION_QNAME.equals(name)) {
+    
+                            // Read an <operation>
+                            Operation operation = new OperationImpl();
+                            operation.setName(getString(reader, NAME));
+                            operation.setUnresolved(true);
+                            policyProcessor.readPolicies(abstractContract, operation, reader);
+                            
+                        } else {
+    
+                            // Read an extension element
+                            Object extension = extensionProcessor.read(reader);
+                            if (extension instanceof InterfaceContract) {
+                                
+                                // <service><interface> and <reference><interface>
+                                abstractContract.setInterfaceContract((InterfaceContract)extension);
+                            } else {
+    
+                                // Add the extension element to the current element
+                                if (abstractContract != null) {
+                                    abstractContract.getExtensions().add(extension);
+                                } else {
+                                    constrainingType.getExtensions().add(extension);
+                                }
+                                
+                            }
+                        }
+                        break;
+    
+                    case END_ELEMENT:
+                        name = reader.getName();
+    
+                        // Clear current state when reading reaching end element
+                        if (SERVICE_QNAME.equals(name)) {
+                            abstractService = null;
+                            abstractContract = null;
+                        } else if (REFERENCE_QNAME.equals(name)) {
+                            abstractReference = null;
+                            abstractContract = null;
+                        } else if (PROPERTY_QNAME.equals(name)) {
+                            abstractProperty = null;
+                        }
+                        break;
+                }
+                if (reader.hasNext()) {
+                    reader.next();
+                }
+            }
+        }
+        catch (XMLStreamException e) {
+            ContributionReadException ex = new ContributionReadException(e);
+            error("XMLStreamException", reader, ex);
+        }
+        
+        return constrainingType;
+    }
+    
+    public void write(ConstrainingType constrainingType, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {
+
+        // Write <constrainingType> element
+        writeStartDocument(writer, CONSTRAINING_TYPE,
+           new XAttr(TARGET_NAMESPACE, constrainingType.getName().getNamespaceURI()),
+           new XAttr(NAME, constrainingType.getName().getLocalPart()),
+           policyProcessor.writePolicies(constrainingType));
+
+        // Write <service> elements 
+        for (AbstractService service : constrainingType.getServices()) {
+            writeStart(writer, SERVICE, new XAttr(NAME, service.getName()),
+                       policyProcessor.writePolicies(service));
+            
+            extensionProcessor.write(service.getInterfaceContract(), writer);
+
+            for (Object extension: service.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+            
+            writeEnd(writer);
+        }
+
+        // Write <reference> elements
+        for (AbstractReference reference : constrainingType.getReferences()) {
+            writeStart(writer, REFERENCE, new XAttr(NAME, reference.getName()),
+                       writeMultiplicity(reference),
+                       policyProcessor.writePolicies(reference));
+            
+            extensionProcessor.write(reference.getInterfaceContract(), writer);
+
+            for (Object extension: reference.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+            
+            writeEnd(writer);
+        }
+
+        // Write <property> elements
+        for (AbstractProperty abstractProperty : constrainingType.getProperties()) {
+            writeStart(writer,
+                       PROPERTY,
+                       new XAttr(NAME, abstractProperty.getName()),
+                       new XAttr(MUST_SUPPLY, abstractProperty.isMustSupply()),
+                       new XAttr(MANY, abstractProperty.isMany()),
+                       new XAttr(TYPE, abstractProperty.getXSDType()),
+                       new XAttr(ELEMENT, abstractProperty.getXSDElement()),
+                       policyProcessor.writePolicies(abstractProperty));
+
+            // Write property value
+            writePropertyValue(abstractProperty.getValue(), abstractProperty.getXSDElement(), abstractProperty.getXSDType(), writer);
+
+            // Write extensions
+            for (Object extension : abstractProperty.getExtensions()) {
+                extensionProcessor.write(extension, writer);
+            }
+
+            writeEnd(writer);
+        }
+
+        // Write extension elements
+        for (Object extension: constrainingType.getExtensions()) {
+            extensionProcessor.write(extension, writer);
+        }
+        
+        writeEndDocument(writer);
+    }
+    
+    public void resolve(ConstrainingType constrainingType, ModelResolver resolver) throws ContributionResolveException {
+        // Resolve component type services and references
+        resolveAbstractContracts(constrainingType.getServices(), resolver);
+        resolveAbstractContracts(constrainingType.getReferences(), resolver);
+    }
+    
+    public QName getArtifactType() {
+        return CONSTRAINING_TYPE_QNAME;
+    }
+    
+    public Class<ConstrainingType> getModelType() {
+        return ConstrainingType.class;
+    }
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/DefaultBeanModelProcessor.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/DefaultBeanModelProcessor.java
new file mode 100644
index 0000000000..e525cc677a
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/DefaultBeanModelProcessor.java
@@ -0,0 +1,254 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import static javax.xml.stream.XMLStreamConstants.END_ELEMENT;
+
+import java.lang.reflect.Method;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+
+import org.apache.tuscany.sca.assembly.Base;
+import org.apache.tuscany.sca.assembly.ComponentType;
+import org.apache.tuscany.sca.assembly.Implementation;
+import org.apache.tuscany.sca.contribution.processor.ContributionReadException;
+import org.apache.tuscany.sca.contribution.processor.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.processor.ContributionWriteException;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.monitor.Monitor;
+import org.apache.tuscany.sca.policy.PolicySubject;
+
+/**
+ * Default Model Processor for beans.
+ *
+ * @version $Rev$ $Date$
+ */
+public class DefaultBeanModelProcessor extends BaseAssemblyProcessor implements StAXArtifactProcessor {
+
+    private QName artifactType;
+    private Class<Implementation> modelClass;
+    private Object modelFactory;
+    private Method factoryMethod;
+    private Map<String, Method> setterMethods = new HashMap<String, Method>();
+    private Map<String, Method> getterMethods = new HashMap<String, Method>();
+
+    public DefaultBeanModelProcessor(FactoryExtensionPoint modeFactories,
+                                     QName artifactType,
+                                     Class<Implementation> modelClass,
+                                     Object modelFactory,
+                                     Monitor monitor) {
+        super(modeFactories, null, monitor);
+        this.artifactType = artifactType;
+        this.modelClass = modelClass;
+        this.modelFactory = modelFactory;
+        
+        // Introspect the factory class and bean model class
+        if (modelFactory != null) {
+            
+            // Find the model create method
+            for (Method method: modelFactory.getClass().getMethods()) {
+                if (method.getName().startsWith("create") && method.getReturnType() == modelClass) {
+                    factoryMethod = method;
+                    break;
+                }
+            }
+        }
+        
+        // Index the bean's setter methods
+        for (Method method: modelClass.getMethods()) {
+            Method getter;
+            String name = method.getName();
+            if (name.startsWith("set") && name.length() > 3) {
+                
+                // Get the corresponding getter method
+                try {
+                    getter = modelClass.getMethod("get" + name.substring(3));
+                } catch (Exception e) {
+                    getter = null;
+                    continue;
+                }
+                
+                // Get the property name
+                name = name.substring(3);
+                if (name.length() > 1) {
+                    if (!name.toUpperCase().equals(name)) {
+                        name = name.substring(0, 1).toLowerCase() + name.substring(1);
+                    }
+                }
+            } else {
+                continue;
+            }
+            
+            // Map an uppercase property name to a lowercase attribute name 
+            if (name.toUpperCase().equals(name)) {
+                name = name.toLowerCase();
+            }
+            
+            // Trim trailing _ from property names
+            if (name.endsWith("_")) {
+                name = name.substring(0, name.length()-1);
+            }
+            setterMethods.put(name, method);
+            getterMethods.put(name, getter);
+        }
+    }
+
+    public Object read(XMLStreamReader reader) throws ContributionReadException, XMLStreamException {
+
+        // Read an element
+        try {
+            
+            // Create a new instance of the model
+            Object model;
+            if (modelFactory != null) {
+                // Invoke the factory create method
+                model = factoryMethod.invoke(modelFactory);
+            } else {
+                // Invoke the model bean class default constructor
+                model = modelClass.newInstance();
+            }
+
+            // Initialize the bean properties with the attributes found in the
+            // XML element
+            for (int i = 0, n = reader.getAttributeCount(); i < n; i++) {
+                String attributeName = reader.getAttributeLocalName(i);
+                Method setter = setterMethods.get(attributeName);
+                if (setter != null) {
+                    String value = reader.getAttributeValue(i);
+                    setter.invoke(model, value);
+                }
+            }
+
+            // Read policies
+            policyProcessor.readPolicies(model, reader);
+
+            // FIXME read extension elements
+            
+            // By default mark the model object unresolved
+            if (model instanceof Base) {
+                ((Base)model).setUnresolved(true);
+            }
+            
+            // Skip to end element
+            while (reader.hasNext()) {
+                if (reader.next() == END_ELEMENT && artifactType.equals(reader.getName())) {
+                    break;
+                }
+            }
+            return model;
+
+        } catch (Exception e) {
+        	ContributionReadException ce = new ContributionReadException(e);
+        	error("ContributionReadException", reader, ce);
+            throw ce;
+        }
+    }
+
+    public void write(Object bean, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {
+        try {
+            // Write the bean properties as attributes
+            List<XAttr> attrs = new ArrayList<XAttr>();
+            for (Map.Entry<String, Method> entry: getterMethods.entrySet()) {
+                if (entry.getValue().getReturnType() == String.class) {
+                    String value = (String)entry.getValue().invoke(bean);
+                    attrs.add(new XAttr(entry.getKey(), value));
+                }
+            }
+            
+            // Write element
+            writeStart(writer, artifactType.getNamespaceURI(), artifactType.getLocalPart(),
+                       policyProcessor.writePolicies(bean), new XAttr(null, attrs));
+
+            writeEnd(writer);
+
+        } catch (Exception e) {
+        	ContributionWriteException ce = new ContributionWriteException(e);
+        	error("ContributionWriteException", writer, ce);
+            throw ce;
+        }
+    }
+
+    public void resolve(Object bean, ModelResolver resolver) throws ContributionResolveException {
+        
+        // Resolve and merge the component type associated with an
+        // implementation model
+        if (bean instanceof Implementation) {
+            Implementation implementation = (Implementation)bean;
+            String uri = implementation.getURI();
+            if (uri != null) {
+                int d = uri.lastIndexOf('.');
+                if (d != -1) {
+                    uri = uri.substring(0, d) + ".componentType";
+                    
+                    // Resolve the component type
+                    ComponentType componentType = assemblyFactory.createComponentType();
+                    componentType.setURI(uri);
+                    componentType.setUnresolved(true);
+                    
+                    componentType = resolver.resolveModel(ComponentType.class, componentType);
+                    if (componentType != null && !componentType.isUnresolved()) {
+                        
+                        // We found a component type, merge it into the implementation model
+                        implementation.getServices().addAll(componentType.getServices());
+                        implementation.getReferences().addAll(componentType.getReferences());
+                        implementation.getProperties().addAll(componentType.getProperties());
+                        implementation.setConstrainingType(componentType.getConstrainingType());
+                        
+                        if (implementation instanceof PolicySubject &&
+                                componentType instanceof PolicySubject ) {
+                            PolicySubject policiedImpl = (PolicySubject)implementation;
+                            PolicySubject policiedCompType = (PolicySubject)componentType;
+                            
+                            if ( policiedImpl.getPolicySets() != null) {
+                                policiedImpl.getPolicySets().addAll(policiedCompType.getPolicySets());
+                            }
+                            if (policiedImpl.getRequiredIntents() != null) {
+                                policiedImpl.getRequiredIntents().addAll(policiedCompType.getRequiredIntents());
+                            }
+                        }
+                    }
+                }
+            }
+        }
+        
+        // Mark the model resolved
+        if (bean instanceof Base) {
+            ((Base)bean).setUnresolved(false);
+        }
+    }
+
+    public QName getArtifactType() {
+        return artifactType;
+    }
+
+    public Class<?> getModelType() {
+        return modelClass;
+    }
+
+}
diff --git a/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/PolicySubjectProcessor.java b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/PolicySubjectProcessor.java
new file mode 100644
index 0000000000..d69f30aceb
--- /dev/null
+++ b/sca-java-2.x/branches/sca-java-2.0-M2/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/PolicySubjectProcessor.java
@@ -0,0 +1,252 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+
+package org.apache.tuscany.sca.assembly.xml;
+
+import static org.apache.tuscany.sca.assembly.xml.Constants.POLICY_SETS;
+import static org.apache.tuscany.sca.assembly.xml.Constants.REQUIRES;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.StringTokenizer;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+
+import org.apache.tuscany.sca.contribution.processor.BaseStAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.interfacedef.Operation;
+import org.apache.tuscany.sca.policy.Intent;
+import org.apache.tuscany.sca.policy.PolicyFactory;
+import org.apache.tuscany.sca.policy.PolicySet;
+import org.apache.tuscany.sca.policy.PolicySubject;
+
+/**
+ * A Policy Attach Point processor.
+ *
+ * @version $Rev$ $Date$
+ */
+public class PolicySubjectProcessor extends BaseStAXArtifactProcessor {
+    
+    private PolicyFactory policyFactory;
+    
+    public PolicySubjectProcessor(PolicyFactory policyFactory) {
+        this.policyFactory = policyFactory;
+    }
+
+    /**
+     * Read policy intents associated with an operation.
+     * @param attachPoint
+     * @param operation
+     * @param reader
+     */
+    private void readIntents(Object attachPoint, Operation operation, XMLStreamReader reader) {
+        if (!(attachPoint instanceof PolicySubject))
+            return;
+        PolicySubject intentAttachPoint = (PolicySubject)attachPoint;
+        String value = reader.getAttributeValue(null, REQUIRES);
+        if (value != null) {
+            List<Intent> requiredIntents = intentAttachPoint.getRequiredIntents();
+            for (StringTokenizer tokens = new StringTokenizer(value); tokens.hasMoreTokens();) {
+                QName qname = getQNameValue(reader, tokens.nextToken());
+                Intent intent = policyFactory.createIntent();
+                intent.setName(qname);
+                if (operation != null) {
+                    //FIXME Don't we need to handle intent specification
+                    // on an operation basis?
+                    //intent.getOperations().add(operation);
+                }
+                requiredIntents.add(intent);
+            }
+        }
+    }
+
+    /**
+     * Reads policy intents and policy sets associated with an operation.
+     * @param attachPoint
+     * @param operation
+     * @param reader
+     */
+    public void readPolicies(Object attachPoint, Operation operation, XMLStreamReader reader) {
+        readIntents(attachPoint, operation, reader);
+        readPolicySets(attachPoint, operation, reader);
+    }
+
+    /**
+     * Reads policy intents and policy sets.
+     * @param attachPoint
+     * @param reader
+     */
+    public void readPolicies(Object attachPoint, XMLStreamReader reader) {
+        readPolicies(attachPoint, null, reader);
+    }
+
+    /**
+     * Reads policy sets associated with an operation.
+     * @param attachPoint
+     * @param operation
+     * @param reader
+     */
+    private void readPolicySets(Object attachPoint, Operation operation, XMLStreamReader reader) {
+        if (!(attachPoint instanceof PolicySubject)) {
+            return;
+        }
+        PolicySubject policySubject = (PolicySubject)attachPoint;
+        String value = reader.getAttributeValue(null, POLICY_SETS);
+        if (value != null) {
+            List<PolicySet> policySets = policySubject.getPolicySets();
+            for (StringTokenizer tokens = new StringTokenizer(value); tokens.hasMoreTokens();) {
+                QName qname = getQNameValue(reader, tokens.nextToken());
+                PolicySet policySet = policyFactory.createPolicySet();
+                policySet.setName(qname);
+                if (operation != null) {
+                    //FIXME Don't we need to handle policySet specification
+                    // on an operation basis?
+                    //policySet.getOperations().add(operation);
+                }
+                policySets.add(policySet);
+            }
+        }
+    }
+    
+    /**
+     * Write policies
+     * @param attachPoint
+     * @return
+     */
+    XAttr writePolicies(Object attachPoint) throws XMLStreamException {
+        return writePolicies(attachPoint, (Operation)null);
+    }
+
+    /**
+     * Write policies
+     * @param attachPoint
+     * @return
+     */
+    public void writePolicyAttributes(Object attachPoint, XMLStreamWriter writer) throws XMLStreamException {
+        writePolicyAttributes(attachPoint, (Operation)null, writer);
+    }
+
+    /**
+     * Write policies
+     * @param attachPoint
+     * @return
+     */
+    public void writePolicyPrefixes(Object attachPoint, XMLStreamWriter writer) throws XMLStreamException {
+        writePolicyPrefixes(attachPoint, (Operation)null, writer);
+    }
+
+    /**
+     * Write policies associated with an operation
+     * @param attachPoint
+     * @param operation
+     * @return
+     */
+    XAttr writePolicies(Object attachPoint, Operation operation) {
+        List<XAttr> attrs =new ArrayList<XAttr>();
+        attrs.add(writeIntents(attachPoint, operation));
+        attrs.add(writePolicySets(attachPoint, operation));
+        return new XAttr(null, attrs);
+    }
+
+    /**
+     * Write policies
+     * @param attachPoint
+     * @return
+     */
+    public void writePolicyAttributes(Object attachPoint, Operation operation, XMLStreamWriter writer) throws XMLStreamException {
+        XAttr attr = writePolicies(attachPoint, operation);
+        attr.write(writer);
+    }
+
+    /**
+     * Write policies
+     * @param attachPoint
+     * @return
+     */
+    public void writePolicyPrefixes(Object attachPoint, Operation operation, XMLStreamWriter writer) throws XMLStreamException {
+        XAttr attr = writePolicies(attachPoint, operation);
+        attr.writePrefix(writer);
+    }
+
+    /**
+     * Write policy intents associated with an operation.
+     * @param attachPoint
+     * @param operation
+     */
+    private XAttr writeIntents(Object attachPoint, Operation operation) {
+        if (!(attachPoint instanceof PolicySubject)) {
+            return null;
+        }
+        PolicySubject intentAttachPoint = (PolicySubject)attachPoint;
+        List<QName> qnames = new ArrayList<QName>();
+        for (Intent intent: intentAttachPoint.getRequiredIntents()) {
+            qnames.add(intent.getName());
+        }
+        return new XAttr(Constants.REQUIRES, qnames);
+    }
+
+    /**
+     * Write policy sets associated with an operation.
+     * @param attachPoint
+     * @param operation
+     */
+    private XAttr writePolicySets(Object attachPoint, Operation operation) {
+        if (!(attachPoint instanceof PolicySubject)) {
+            return null;
+        }
+        PolicySubject policySetAttachPoint = (PolicySubject)attachPoint;
+        List<QName> qnames = new ArrayList<QName>();
+        for (PolicySet policySet: policySetAttachPoint.getPolicySets()) {
+            qnames.add(policySet.getName());
+        }
+        return new XAttr(Constants.POLICY_SETS, qnames);
+    }
+    
+    public void resolvePolicies(Object attachPoint, ModelResolver resolver) {
+        if ( attachPoint instanceof PolicySubject ) {
+            PolicySubject policySetAttachPoint = (PolicySubject)attachPoint;
+            
+            List<Intent> requiredIntents = new ArrayList<Intent>();
+            Intent resolvedIntent = null;
+            
+            if ( policySetAttachPoint.getRequiredIntents() != null && policySetAttachPoint.getRequiredIntents().size() > 0 ) {
+                for ( Intent intent : policySetAttachPoint.getRequiredIntents() ) {
+                    resolvedIntent = resolver.resolveModel(Intent.class, intent);
+                    requiredIntents.add(resolvedIntent);
+                }
+                policySetAttachPoint.getRequiredIntents().clear();
+                policySetAttachPoint.getRequiredIntents().addAll(requiredIntents);
+            }
+            
+            if ( policySetAttachPoint.getPolicySets() != null && policySetAttachPoint.getPolicySets().size() > 0 ) {
+                List<PolicySet> resolvedPolicySets = new ArrayList<PolicySet>();
+                PolicySet resolvedPolicySet = null;
+                for ( PolicySet policySet : policySetAttachPoint.getPolicySets() ) {
+                    resolvedPolicySet = resolver.resolveModel(PolicySet.class, policySet);
+                    resolvedPolicySets.add(resolvedPolicySet);
+                }
+                policySetAttachPoint.getPolicySets().clear();
+                policySetAttachPoint.getPolicySets().addAll(resolvedPolicySets);
+            }
+        }
+    }
+}