TUSCANY-2463 - Adding attribute extension infrastructure and integration with basic sca model parsing

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@694165 13f79535-47bb-0310-9956-ffa450edef68

13 files changed, 1143 insertions, 64 deletions

diff --git a/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/BaseAssemblyProcessor.java b/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/BaseAssemblyProcessor.java
index ae33a4da16..06b208540a 100644
--- a/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/BaseAssemblyProcessor.java
+++ b/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/BaseAssemblyProcessor.java
@@ -49,6 +49,7 @@ import org.apache.tuscany.sca.assembly.Composite;
 import org.apache.tuscany.sca.assembly.ConfiguredOperation;
 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.Implementation;
 import org.apache.tuscany.sca.assembly.Multiplicity;
 import org.apache.tuscany.sca.assembly.OperationsConfigurator;
@@ -58,9 +59,11 @@ import org.apache.tuscany.sca.assembly.builder.impl.ProblemImpl;
 import org.apache.tuscany.sca.contribution.ContributionFactory;
 import org.apache.tuscany.sca.contribution.processor.BaseStAXArtifactProcessor;
 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.service.ContributionReadException;
 import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
 import org.apache.tuscany.sca.interfacedef.InterfaceContract;
 import org.apache.tuscany.sca.monitor.Monitor;
 import org.apache.tuscany.sca.monitor.Problem;
@@ -832,6 +835,45 @@ abstract class BaseAssemblyProcessor extends BaseStAXArtifactProcessor implement
         }
     }
     
+    /**
+     * 
+     * @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()) ) {
+             		String attributeExtension = (String) extensionAttributeProcessor.read(attributeName, reader);
+             		estensibleElement.getExtensions().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(Object o : extensibleElement.getExtensions()) {
+        	//FIXME How to identify it's a extended attribute ? 
+        	if(o instanceof String) {
+        		extensionAttributeProcessor.write(o, writer);
+        	}
+        }
+    }
     
     /*protected void validatePolicySets(PolicySetAttachPoint policySetAttachPoint) 
                                                             throws ContributionResolveException {
diff --git a/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeProcessor.java b/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeProcessor.java
index 73a64702e4..9727b89aab 100644
--- a/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeProcessor.java
+++ b/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/ComponentTypeProcessor.java
@@ -38,6 +38,7 @@ import org.apache.tuscany.sca.assembly.Reference;
 import org.apache.tuscany.sca.assembly.Service;
 import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
 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.service.ContributionReadException;
 import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
@@ -45,10 +46,10 @@ import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
 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.IntentAttachPoint;
 import org.apache.tuscany.sca.policy.PolicyFactory;
 import org.apache.tuscany.sca.policy.PolicySetAttachPoint;
-import org.apache.tuscany.sca.monitor.Monitor;
 import org.w3c.dom.Document;
 
 /**
@@ -65,7 +66,7 @@ public class ComponentTypeProcessor extends BaseAssemblyProcessor implements StA
      * @param registry
      */
     public ComponentTypeProcessor(AssemblyFactory factory, PolicyFactory policyFactory, 
-    							  StAXArtifactProcessor extensionProcessor, Monitor monitor) {
+    							  StAXArtifactProcessor extensionProcessor, StAXAttributeProcessor extensionAttributeProcessor, Monitor monitor) {
         super(factory, policyFactory, extensionProcessor, monitor);
     }
 
@@ -77,6 +78,7 @@ public class ComponentTypeProcessor extends BaseAssemblyProcessor implements StA
      */
     public ComponentTypeProcessor(ModelFactoryExtensionPoint modelFactories, 
     							  StAXArtifactProcessor extensionProcessor,
+    							  StAXAttributeProcessor extensionAttributeProcessor,
     							  Monitor monitor) {
         super(modelFactories.getFactory(AssemblyFactory.class),
               modelFactories.getFactory(PolicyFactory.class), extensionProcessor, monitor);
diff --git a/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeProcessor.java b/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeProcessor.java
index c1a8bb5b86..09ec7664ce 100644
--- a/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeProcessor.java
+++ b/java/sca/modules/assembly-xml/src/main/java/org/apache/tuscany/sca/assembly/xml/CompositeProcessor.java
@@ -59,6 +59,7 @@ import org.apache.tuscany.sca.contribution.Artifact;
 import org.apache.tuscany.sca.contribution.ContributionFactory;
 import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
 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.contribution.service.ContributionReadException;
@@ -88,16 +89,25 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
     // FIXME: to be refactored
     private XPathFactory xPathFactory = XPathFactory.newInstance();
     
+    protected StAXAttributeProcessor<Object> extensionAttributeProcessor;
+    
     /**
      * Construct a new composite processor
      * 
      * @param extensionPoints
      * @param extensionProcessor
      */
-    public CompositeProcessor(ExtensionPointRegistry extensionPoints, 
-    						  StAXArtifactProcessor extensionProcessor,
-    						  Monitor monitor) {
-        this(modelFactories(extensionPoints), extensionProcessor, monitor(extensionPoints));
+    public CompositeProcessor(ExtensionPointRegistry extensionPoints,
+			StAXArtifactProcessor extensionProcessor,
+			StAXAttributeProcessor extensionAttributeProcessor, 
+			Monitor monitor) {
+        
+    	this(modelFactories(extensionPoints), 
+    		extensionProcessor, 
+    		extensionAttributeProcessor, 
+    		monitor(extensionPoints));
+        
+    	this.extensionAttributeProcessor = extensionAttributeProcessor;
     }
     
     /**
@@ -108,12 +118,18 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
      * @param monitor
      */
     private CompositeProcessor(ModelFactoryExtensionPoint modelFactories,
-                               StAXArtifactProcessor extensionProcessor,
-                               Monitor monitor) {
-        super(modelFactories.getFactory(ContributionFactory.class),
+             StAXArtifactProcessor extensionProcessor,
+             StAXAttributeProcessor extensionAttributeProcessor,
+             Monitor monitor) {
+        
+    	super(modelFactories.getFactory(ContributionFactory.class),
             modelFactories.getFactory(AssemblyFactory.class),
             modelFactories.getFactory(PolicyFactory.class),
-            extensionProcessor, monitor);
+            extensionProcessor, 
+            monitor);
+        
+        this.extensionAttributeProcessor = extensionAttributeProcessor;
+        
     }
     
     /**
@@ -125,10 +141,11 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
      * @param extensionProcessor
      */
     public CompositeProcessor(ContributionFactory contributionFactory,
-                              AssemblyFactory assemblyFactory,
-                              PolicyFactory policyFactory,
-                              StAXArtifactProcessor extensionProcessor,
-                              Monitor monitor) {
+            AssemblyFactory assemblyFactory,
+            PolicyFactory policyFactory,
+            StAXArtifactProcessor extensionProcessor,
+            StAXAttributeProcessor extensionAttributeProcessor,
+            Monitor monitor) {
         super(contributionFactory, assemblyFactory, policyFactory, extensionProcessor, monitor);
     }    
 
@@ -169,6 +186,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                         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);
@@ -189,6 +210,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                             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 {
@@ -222,6 +247,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                                 compositeService.setPromotedService(promotedService);
                             }
 
+                            //handle extension attributes
+                            this.readExtendedAttributes(reader, name, compositeService, extensionAttributeProcessor);
+
                             composite.getServices().add(compositeService);
                             policyProcessor.readPolicies(contract, reader);
                         }
@@ -238,6 +266,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                             }
                             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 {
@@ -258,7 +290,11 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                                 }
                             }
                             compositeReference.setWiredByImpl(getBoolean(reader, WIRED_BY_IMPL));
-                            composite.getReferences().add(compositeReference);
+                            
+                            //handle extension attributes
+                            this.readExtendedAttributes(reader, name, compositeReference, extensionAttributeProcessor);
+
+                            composite.getReferences().add(compositeReference);                            
                             policyProcessor.readPolicies(contract, reader);
                         }
 
@@ -298,6 +334,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                                 }
                             }
                             componentProperty.setFile(getString(reader, FILE));
+                            
+                            //handle extension attributes
+                            this.readExtendedAttributes(reader, name, componentProperty, extensionAttributeProcessor);
+
                             policyProcessor.readPolicies(property, reader);
                             readAbstractProperty(componentProperty, reader);
                             
@@ -338,6 +378,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                         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);
@@ -356,6 +400,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                         target.setName(getString(reader, TARGET));
                         wire.setTarget(target);
 
+                        //handle extension attributes
+                        this.readExtendedAttributes(reader, name, wire, extensionAttributeProcessor);
+
                         composite.getWires().add(wire);
                         policyProcessor.readPolicies(wire, reader);
 
@@ -364,6 +411,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                         // Read a <callback>
                         callback = assemblyFactory.createCallback();
                         contract.setCallback(callback);
+                        
+                        //handle extension attributes
+                        this.readExtendedAttributes(reader, name, callback, extensionAttributeProcessor);
+                        
                         policyProcessor.readPolicies(callback, reader);
 
                     } else if (OPERATION_QNAME.equals(name)) {
@@ -396,6 +447,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                         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 {
@@ -527,6 +582,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                            new XAttr(NAME, composite.getName().getLocalPart()),
                            new XAttr(AUTOWIRE, composite.getAutowire()),
                            policyProcessor.writePolicies(composite));
+        
+        //write extended attributes
+        this.writeExtendedAttributes(writer, composite, extensionAttributeProcessor);
 
         // Write <include> elements
         for (Composite include : composite.getIncludes()) {
@@ -535,6 +593,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                        INCLUDE,
                        new XAttr(NAME, include.getName()),
                        new XAttr(URI, uri));
+
+            //write extended attributes
+            this.writeExtendedAttributes(writer, include, extensionAttributeProcessor);
+            
             writeEnd(writer);
         }
 
@@ -556,6 +618,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
             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);
 
@@ -570,6 +636,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                 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);
@@ -598,10 +667,17 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                        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);
@@ -612,6 +688,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                 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);
                 
@@ -624,7 +703,10 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                 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);
@@ -653,6 +735,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                            writeTargets(reference),
                            policyProcessor.writePolicies(reference));
 
+                //write extended attributes
+                this.writeExtendedAttributes(writer, reference, extensionAttributeProcessor);
+
                 // Write reference interface
                 extensionProcessor.write(reference.getInterfaceContract(), writer);
 
@@ -666,6 +751,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                     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);
@@ -700,6 +788,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                            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);
 
@@ -729,6 +820,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                        new XAttr(PROMOTE, promote),
                        policyProcessor.writePolicies(reference));
 
+            //write extended attributes
+            this.writeExtendedAttributes(writer, reference, extensionAttributeProcessor);
+
             // Write reference interface
             extensionProcessor.write(reference.getInterfaceContract(), writer);
             
@@ -742,6 +836,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                 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);
@@ -774,6 +871,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
                        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);
 
@@ -790,6 +890,9 @@ public class CompositeProcessor extends BaseAssemblyProcessor implements StAXArt
             writeStart(writer, WIRE, new XAttr(SOURCE, wire.getSource().getName()), new XAttr(TARGET, wire
                 .getTarget().getName()));
             
+            //write extended attributes
+            this.writeExtendedAttributes(writer, wire, extensionAttributeProcessor);
+
             // Write extensions
             for (Object extension : wire.getExtensions()) {
                 extensionProcessor.write(extension, writer);
diff --git a/java/sca/modules/assembly-xml/src/test/java/org/apache/tuscany/sca/assembly/xml/ReadWriteAttributeTestCase.java b/java/sca/modules/assembly-xml/src/test/java/org/apache/tuscany/sca/assembly/xml/ReadWriteAttributeTestCase.java
new file mode 100644
index 0000000000..437b8928b1
--- /dev/null
+++ b/java/sca/modules/assembly-xml/src/test/java/org/apache/tuscany/sca/assembly/xml/ReadWriteAttributeTestCase.java
@@ -0,0 +1,106 @@
+/*
+ * 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.ByteArrayOutputStream;
+import java.io.InputStream;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLOutputFactory;
+import javax.xml.stream.XMLStreamReader;
+
+import junit.framework.TestCase;
+
+import org.apache.tuscany.sca.assembly.Composite;
+import org.apache.tuscany.sca.contribution.processor.ExtensibleStAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessor;
+import org.apache.tuscany.sca.contribution.processor.StAXArtifactProcessorExtensionPoint;
+import org.apache.tuscany.sca.contribution.processor.StAXAttributeProcessorExtensionPoint;
+import org.apache.tuscany.sca.core.DefaultExtensionPointRegistry;
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+
+/**
+ * Test reading SCA XML assemblies.
+ * 
+ * @version $Rev$ $Date$
+ */
+public class ReadWriteAttributeTestCase extends TestCase {
+
+    private XMLInputFactory inputFactory;
+    private ExtensibleStAXArtifactProcessor staxProcessor;
+
+    private static final QName ATTRIBUTE = new QName("http://test", "customAttribute");
+    
+    private static final String XML = 
+    	"<?xml version='1.0' encoding='UTF-8'?>" +
+    	"<composite xmlns=\"http://www.osoa.org/xmlns/sca/1.0\" xmlns:ns1=\"http://www.osoa.org/xmlns/sca/1.0\" targetNamespace=\"http://calc\" name=\"Calculator\">" + 
+    	"<service name=\"CalculatorService\" promote=\"CalculatorServiceComponent\" />" +
+    	"<component name=\"CalculatorServiceComponent\" customAttribute=\"customValue\">" + 
+    	   "<reference name=\"addService\" target=\"AddServiceComponent\" />" +
+    	   "<reference name=\"subtractService\" target=\"SubtractServiceComponent\" />"+
+    	   "<reference name=\"multiplyService\" target=\"MultiplyServiceComponent\" />" + 
+    	   "<reference name=\"divideService\" target=\"DivideServiceComponent\" />" + 
+    	"</component>"+
+    	"<component name=\"AddServiceComponent\" />" + 
+    	"<component name=\"SubtractServiceComponent\" />" + 
+    	"<component name=\"MultiplyServiceComponent\" />" + 
+    	"<component name=\"DivideServiceComponent\" />" + 
+    	"</composite>";
+    
+    @Override
+    public void setUp() throws Exception {
+        ExtensionPointRegistry extensionPoints = new DefaultExtensionPointRegistry();
+        inputFactory = XMLInputFactory.newInstance();
+        StAXArtifactProcessorExtensionPoint staxProcessors = extensionPoints.getExtensionPoint(StAXArtifactProcessorExtensionPoint.class);
+
+        StAXAttributeProcessorExtensionPoint staxAttributeProcessors = extensionPoints.getExtensionPoint(StAXAttributeProcessorExtensionPoint.class);
+        staxAttributeProcessors.addArtifactProcessor(new TestAttributeProcessor());
+        
+        
+        staxProcessor = new ExtensibleStAXArtifactProcessor(staxProcessors, XMLInputFactory.newInstance(), XMLOutputFactory.newInstance(), null);
+    }
+
+    @Override
+    public void tearDown() throws Exception {
+    	
+    }
+
+    public void testReadComposite() throws Exception {
+        InputStream is = getClass().getResourceAsStream("CalculatorExtended.composite");
+        XMLStreamReader reader = inputFactory.createXMLStreamReader(is);
+        Composite composite = (Composite) staxProcessor.read(reader);
+        assertNotNull(composite);
+        is.close();
+    }
+    
+    public void testWriteComposite() throws Exception {
+        InputStream is = getClass().getResourceAsStream("CalculatorExtended.composite");
+        XMLStreamReader reader = inputFactory.createXMLStreamReader(is);
+        Composite composite = (Composite) staxProcessor.read(reader);
+        assertNotNull(composite);
+        is.close();
+        
+        ByteArrayOutputStream bos = new ByteArrayOutputStream();
+        staxProcessor.write(composite, bos);
+        
+        assertEquals(XML, bos.toString());
+    }
+}
diff --git a/java/sca/modules/assembly-xml/src/test/java/org/apache/tuscany/sca/assembly/xml/TestAttributeProcessor.java b/java/sca/modules/assembly-xml/src/test/java/org/apache/tuscany/sca/assembly/xml/TestAttributeProcessor.java
new file mode 100644
index 0000000000..691145a30e
--- /dev/null
+++ b/java/sca/modules/assembly-xml/src/test/java/org/apache/tuscany/sca/assembly/xml/TestAttributeProcessor.java
@@ -0,0 +1,61 @@
+/*
+ * 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;
+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.processor.StAXAttributeProcessor;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.contribution.service.ContributionReadException;
+import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
+
+/**
+ * A Policy Processor used for testing.
+ *
+ * @version $Rev$ $Date$
+ */
+public class TestAttributeProcessor extends BaseStAXArtifactProcessor implements StAXAttributeProcessor<String> {
+	private static final QName ATTRIBUTE = new QName("http://test", "customAttribute");
+	
+    public QName getArtifactType() {
+        return ATTRIBUTE;
+    }
+
+    public String read(QName attributeName, XMLStreamReader reader) throws ContributionReadException, XMLStreamException {
+        return reader.getAttributeValue(attributeName.getNamespaceURI(), attributeName.getLocalPart());
+    }
+
+    public void write(String value, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException {
+    	writer.setPrefix(ATTRIBUTE.getPrefix(), ATTRIBUTE.getNamespaceURI());
+    	writer.writeAttribute(ATTRIBUTE.getLocalPart(), value);
+    } 
+
+    public Class<String> getModelType() {
+        return String.class;
+    }
+
+    public void resolve(String arg0, ModelResolver arg1) throws ContributionResolveException {
+    	
+    }
+}
diff --git a/java/sca/modules/assembly-xml/src/test/resources/org/apache/tuscany/sca/assembly/xml/CalculatorExtended.composite b/java/sca/modules/assembly-xml/src/test/resources/org/apache/tuscany/sca/assembly/xml/CalculatorExtended.composite
new file mode 100644
index 0000000000..3c69d0ed67
--- /dev/null
+++ b/java/sca/modules/assembly-xml/src/test/resources/org/apache/tuscany/sca/assembly/xml/CalculatorExtended.composite
@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+ * 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.    
+-->
+<composite xmlns="http://www.osoa.org/xmlns/sca/1.0"
+	xmlns:calc="http://calc"
+	xmlns:test="http://test"
+	targetNamespace="http://calc"
+	name="Calculator">
+
+    <service name="CalculatorService" promote="CalculatorServiceComponent">
+        <interface.java interface="calculator.CalculatorService"/>
+    </service>
+
+    <component name="CalculatorServiceComponent" test:customAttribute="customValue">
+		<implementation.java class="calculator.CalculatorServiceImpl"/>
+        <reference name="addService" target="AddServiceComponent"/>
+        <reference name="subtractService" target="SubtractServiceComponent"/>
+        <reference name="multiplyService" target="MultiplyServiceComponent"/>
+        <reference name="divideService" target="DivideServiceComponent"/>
+    </component>
+
+    <component name="AddServiceComponent">
+        <implementation.java class="calculator.AddServiceImpl"/>
+    </component>
+
+    <component name="SubtractServiceComponent">
+        <implementation.java class="calculator.SubtractServiceImpl"/>
+    </component>
+
+    <component name="MultiplyServiceComponent">
+        <implementation.java class="calculator.MultiplyServiceImpl"/>
+    </component>
+
+    <component name="DivideServiceComponent">
+        <implementation.java class="calculator.DivideServiceImpl"/>
+    </component>
+
+</composite>
diff --git a/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/Constants.java b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/Constants.java
new file mode 100644
index 0000000000..4cf20125b9
--- /dev/null
+++ b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/Constants.java
@@ -0,0 +1,30 @@
+/*
+ * 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.contribution;
+
+/**
+ * Constants used in SCA contribution.
+ *
+ * @version $Rev$ $Date$
+ */
+public interface Constants {
+    String SCA10_NS = "http://www.osoa.org/xmlns/sca/1.0";
+    String SCA10_TUSCANY_NS = "http://tuscany.apache.org/xmlns/sca/1.0";
+}
diff --git a/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/DefaultStAXArtifactProcessorExtensionPoint.java b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/DefaultStAXArtifactProcessorExtensionPoint.java
index db4833886d..f23ebc2c36 100644
--- a/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/DefaultStAXArtifactProcessorExtensionPoint.java
+++ b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/DefaultStAXArtifactProcessorExtensionPoint.java
@@ -60,6 +60,7 @@ public class DefaultStAXArtifactProcessorExtensionPoint extends
     private MonitorFactory monitorFactory;
     private boolean loaded;
     private StAXArtifactProcessor<Object> extensibleStAXProcessor;
+    private StAXAttributeProcessor<Object> extensibleStAXAttributeProcessor;
     private Monitor monitor = null;
 
     /**
@@ -75,6 +76,9 @@ public class DefaultStAXArtifactProcessorExtensionPoint extends
         if (monitorFactory != null)
         	this.monitor = monitorFactory.createMonitor();
         this.extensibleStAXProcessor = new ExtensibleStAXArtifactProcessor(this, inputFactory, outputFactory, this.monitor);
+        
+        StAXAttributeProcessorExtensionPoint attributeExtensionPoint = extensionPoints.getExtensionPoint(StAXAttributeProcessorExtensionPoint.class);
+        this.extensibleStAXAttributeProcessor = new ExtensibleStAXAttributeProcessor(attributeExtensionPoint ,inputFactory, outputFactory, this.monitor);
     }
     
     /**
@@ -182,7 +186,7 @@ public class DefaultStAXArtifactProcessorExtensionPoint extends
             StAXArtifactProcessor processor =
                 new LazyStAXArtifactProcessor(artifactType, modelTypeName, factoryName,
                                               processorDeclaration, extensionPoints, modelFactories, 
-                                              extensibleStAXProcessor, monitor);
+                                              extensibleStAXProcessor,extensibleStAXAttributeProcessor, monitor);
             addArtifactProcessor(processor);
         }
 
@@ -203,6 +207,7 @@ public class DefaultStAXArtifactProcessorExtensionPoint extends
         private StAXArtifactProcessor processor;
         private Class<?> modelType;
         private StAXArtifactProcessor<Object> extensionProcessor;
+        private StAXAttributeProcessor<Object> extensionAttributeProcessor;
         private Monitor monitor;
 
         LazyStAXArtifactProcessor(QName artifactType,
@@ -212,6 +217,7 @@ public class DefaultStAXArtifactProcessorExtensionPoint extends
                                   ExtensionPointRegistry extensionPoints,
                                   ModelFactoryExtensionPoint modelFactories,
                                   StAXArtifactProcessor<Object> extensionProcessor,
+                                  StAXAttributeProcessor<Object> extensionAttributeProcessor,
                                   Monitor monitor) {
 
             this.extensionPoints = extensionPoints;
@@ -220,6 +226,7 @@ public class DefaultStAXArtifactProcessorExtensionPoint extends
             this.factoryName = factoryName;
             this.processorDeclaration = processorDeclaration;
             this.extensionProcessor = extensionProcessor;
+            this.extensionAttributeProcessor = extensionAttributeProcessor;
             this.monitor = monitor;
         }
 
@@ -279,53 +286,66 @@ public class DefaultStAXArtifactProcessorExtensionPoint extends
 
                     // Load and instantiate the processor class
                     try {
-                        Class<StAXArtifactProcessor> processorClass =
-                            (Class<StAXArtifactProcessor>)processorDeclaration.loadClass();
-                        try {
-                            Constructor<StAXArtifactProcessor> constructor =
-                                processorClass.getConstructor(ModelFactoryExtensionPoint.class, Monitor.class);
-                            processor = constructor.newInstance(modelFactories, monitor);
-                        } catch (NoSuchMethodException e) {
-                          try {
-                              Constructor<StAXArtifactProcessor> constructor =
-                                  processorClass.getConstructor(ExtensionPointRegistry.class, Monitor.class);
-                              processor = constructor.newInstance(extensionPoints, monitor);
-                          } catch (NoSuchMethodException e1) {
-                            try {
-                                Constructor<StAXArtifactProcessor> constructor =
-                                    processorClass.getConstructor(ModelFactoryExtensionPoint.class, StAXArtifactProcessor.class, Monitor.class);
-                                processor = constructor.newInstance(modelFactories, extensionProcessor, monitor);
-                            } catch (NoSuchMethodException e2) {
-                                try {
-                                    Constructor<StAXArtifactProcessor> constructor =
-                                        processorClass.getConstructor(ExtensionPointRegistry.class, StAXArtifactProcessor.class, Monitor.class);
-                                    processor = constructor.newInstance(extensionPoints, extensionProcessor, monitor);
-                                } catch (NoSuchMethodException e3) {
-                                    try {
-                                        Constructor<StAXArtifactProcessor> constructor =
-                                            processorClass.getConstructor(ModelFactoryExtensionPoint.class);
-                                        processor = constructor.newInstance(modelFactories);
-                                    } catch (NoSuchMethodException e4) {
-                                      try {
-                                          Constructor<StAXArtifactProcessor> constructor =
-                                              processorClass.getConstructor(ExtensionPointRegistry.class);
-                                          processor = constructor.newInstance(extensionPoints);
-                                      } catch (NoSuchMethodException e4a) {
-                                        try {
-                                            Constructor<StAXArtifactProcessor> constructor =
-                                                processorClass.getConstructor(ModelFactoryExtensionPoint.class, StAXArtifactProcessor.class);
-                                            processor = constructor.newInstance(modelFactories, extensionProcessor);
-                                        } catch (NoSuchMethodException e5) {
-                                            Constructor<StAXArtifactProcessor> constructor =
-                                                processorClass.getConstructor(ExtensionPointRegistry.class, StAXArtifactProcessor.class);
-                                            processor = constructor.newInstance(extensionPoints, extensionProcessor);
-                                        }
-                                      }
-                                    }
-                                }
-                            }
-                          }
-                        }
+                    	Class<StAXArtifactProcessor> processorClass =
+                    		(Class<StAXArtifactProcessor>)processorDeclaration.loadClass();
+                    	try {
+                    		Constructor<StAXArtifactProcessor> constructor =
+                    			processorClass.getConstructor(ModelFactoryExtensionPoint.class, Monitor.class);
+                    		processor = constructor.newInstance(modelFactories, monitor);
+                    	} catch (NoSuchMethodException e) {
+                    		try {
+                    			Constructor<StAXArtifactProcessor> constructor =
+                    				processorClass.getConstructor(ExtensionPointRegistry.class, Monitor.class);
+                    			processor = constructor.newInstance(extensionPoints, monitor);
+                    		} catch (NoSuchMethodException e1) {
+                    			try {
+                    				Constructor<StAXArtifactProcessor> constructor =
+                    					processorClass.getConstructor(ModelFactoryExtensionPoint.class, StAXArtifactProcessor.class, Monitor.class);
+                    				processor = constructor.newInstance(modelFactories, extensionProcessor, monitor);
+                    			} catch (NoSuchMethodException e2) {
+                    				try {
+                    					Constructor<StAXArtifactProcessor> constructor =
+                    						processorClass.getConstructor(ModelFactoryExtensionPoint.class, StAXArtifactProcessor.class, StAXAttributeProcessor.class, Monitor.class);
+                    					processor = constructor.newInstance(modelFactories, extensionProcessor, extensionAttributeProcessor, monitor);
+                    				} catch (NoSuchMethodException e2a) {
+                    					try {
+                    						Constructor<StAXArtifactProcessor> constructor =
+                    							processorClass.getConstructor(ExtensionPointRegistry.class, StAXArtifactProcessor.class, Monitor.class);
+                    						processor = constructor.newInstance(extensionPoints, extensionProcessor, monitor);
+                    					} catch (NoSuchMethodException e3) {
+                    						try {
+                    							Constructor<StAXArtifactProcessor> constructor =
+                    								processorClass.getConstructor(ExtensionPointRegistry.class, StAXArtifactProcessor.class, StAXAttributeProcessor.class, Monitor.class);
+                    							processor = constructor.newInstance(extensionPoints, extensionProcessor, extensionAttributeProcessor, monitor);
+                    						} catch (NoSuchMethodException e3a) {
+
+                    							try {
+                    								Constructor<StAXArtifactProcessor> constructor =
+                    									processorClass.getConstructor(ModelFactoryExtensionPoint.class);
+                    								processor = constructor.newInstance(modelFactories);
+                    							} catch (NoSuchMethodException e4) {
+                    								try {
+                    									Constructor<StAXArtifactProcessor> constructor =
+                    										processorClass.getConstructor(ExtensionPointRegistry.class);
+                    									processor = constructor.newInstance(extensionPoints);
+                    								} catch (NoSuchMethodException e4a) {
+                    									try {
+                    										Constructor<StAXArtifactProcessor> constructor =
+                    											processorClass.getConstructor(ModelFactoryExtensionPoint.class, StAXArtifactProcessor.class);
+                    										processor = constructor.newInstance(modelFactories, extensionProcessor);
+                    									} catch (NoSuchMethodException e5) {
+                    										Constructor<StAXArtifactProcessor> constructor =
+                    											processorClass.getConstructor(ExtensionPointRegistry.class, StAXArtifactProcessor.class);
+                    										processor = constructor.newInstance(extensionPoints, extensionProcessor);
+                    									}
+                    								}
+                    							}
+                    						}
+                    					}
+                    				}
+                    			}
+                    		}
+                    	}
                     } catch (Exception e) {
                     	IllegalStateException ie = new IllegalStateException(e);
                     	error("IllegalStateException", processor, ie);
diff --git a/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/DefaultStAXAttributeProcessorExtensionPoint.java b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/DefaultStAXAttributeProcessorExtensionPoint.java
new file mode 100644
index 0000000000..d81e236b40
--- /dev/null
+++ b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/DefaultStAXAttributeProcessorExtensionPoint.java
@@ -0,0 +1,327 @@
+/*
+ * 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.contribution.processor;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.util.Map;
+import java.util.Set;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLOutputFactory;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+
+import org.apache.tuscany.sca.assembly.builder.impl.ProblemImpl;
+import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.contribution.service.ContributionReadException;
+import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.apache.tuscany.sca.core.UtilityExtensionPoint;
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+import org.apache.tuscany.sca.extensibility.ServiceDiscovery;
+import org.apache.tuscany.sca.monitor.Monitor;
+import org.apache.tuscany.sca.monitor.MonitorFactory;
+import org.apache.tuscany.sca.monitor.Problem;
+import org.apache.tuscany.sca.monitor.Problem.Severity;
+
+/**
+ * The default implementation of an extension point for StAX artifact processors.
+ * 
+ * @version $Rev$ $Date$
+ */
+public class DefaultStAXAttributeProcessorExtensionPoint extends
+    DefaultArtifactProcessorExtensionPoint<StAXAttributeProcessor> implements StAXAttributeProcessorExtensionPoint {
+
+    private ExtensionPointRegistry extensionPoints;
+    private ModelFactoryExtensionPoint modelFactories;
+    private StAXAttributeProcessor<Object> extensibleStAXAttributeProcessor;
+    private boolean loaded;
+    private Monitor monitor = null;
+
+    /**
+     * Constructs a new extension point.
+     */
+    public DefaultStAXAttributeProcessorExtensionPoint(ExtensionPointRegistry extensionPoints) {
+        this.extensionPoints = extensionPoints;
+        this.modelFactories = extensionPoints.getExtensionPoint(ModelFactoryExtensionPoint.class);
+        XMLInputFactory inputFactory = modelFactories.getFactory(XMLInputFactory.class);
+        XMLOutputFactory outputFactory = modelFactories.getFactory(XMLOutputFactory.class);
+        UtilityExtensionPoint utilities = this.extensionPoints.getExtensionPoint(UtilityExtensionPoint.class);
+        MonitorFactory monitorFactory = utilities.getUtility(MonitorFactory.class);
+        if (monitorFactory != null) {
+        	this.monitor = monitorFactory.createMonitor();
+        }
+        this.extensibleStAXAttributeProcessor = new ExtensibleStAXAttributeProcessor(this, inputFactory, outputFactory, this.monitor);
+    }
+    
+    /**
+     * Report a exception.
+     * 
+     * @param problems
+     * @param message
+     * @param model
+    */
+    private void error(String message, Object model, Exception ex) {
+        if (monitor != null) {
+    	    Problem problem = new ProblemImpl(this.getClass().getName(), "contribution-validation-messages", Severity.ERROR, model, message, ex);
+    	    monitor.problem(problem);
+    	}        
+    }
+
+    public void addArtifactProcessor(StAXAttributeProcessor artifactProcessor) {
+        if (artifactProcessor.getArtifactType() != null) {
+            processorsByArtifactType.put((Object)artifactProcessor.getArtifactType(), artifactProcessor);
+        }
+        if (artifactProcessor.getModelType() != null) {
+            processorsByModelType.put(artifactProcessor.getModelType(), artifactProcessor);
+        }
+    }
+
+    public void removeArtifactProcessor(StAXAttributeProcessor artifactProcessor) {
+        if (artifactProcessor.getArtifactType() != null) {
+            processorsByArtifactType.remove((Object)artifactProcessor.getArtifactType());
+        }
+        if (artifactProcessor.getModelType() != null) {
+            processorsByModelType.remove(artifactProcessor.getModelType());
+        }
+    }
+
+    @Override
+    public StAXAttributeProcessor getProcessor(Class<?> modelType) {
+        loadArtifactProcessors();
+        return super.getProcessor(modelType);
+    }
+
+    @Override
+    public StAXAttributeProcessor getProcessor(Object artifactType) {
+        loadArtifactProcessors();
+        return super.getProcessor(artifactType);
+    }
+
+    /**
+     * Returns a QName object from a QName expressed as {ns}name
+     * or ns#name.
+     * 
+     * @param qname
+     * @return
+     */
+    private static QName getQName(String qname) {
+        if (qname == null) {
+            return null;
+        }
+        qname = qname.trim();
+        if (qname.startsWith("{")) {
+            int h = qname.indexOf('}');
+            if (h != -1) {
+                return new QName(qname.substring(1, h), qname.substring(h + 1));
+            }
+        } else {
+            int h = qname.indexOf('#');
+            if (h != -1) {
+                return new QName(qname.substring(0, h), qname.substring(h + 1));
+            }
+        }
+        throw new IllegalArgumentException("Invalid qname: "+qname);
+    }
+
+    /**
+     * Lazily load artifact processors registered in the extension point.
+     */
+    private void loadArtifactProcessors() {
+        if (loaded)
+            return;
+
+        // Get the processor service declarations
+        Set<ServiceDeclaration> processorDeclarations;
+        try {
+            processorDeclarations = ServiceDiscovery.getInstance().getServiceDeclarations(StAXAttributeProcessor.class);
+        } catch (IOException e) {
+        	IllegalStateException ie = new IllegalStateException(e);
+        	error("IllegalStateException", extensibleStAXAttributeProcessor, ie);
+            throw ie;
+        }
+
+        for (ServiceDeclaration processorDeclaration : processorDeclarations) {
+            Map<String, String> attributes = processorDeclaration.getAttributes();
+
+            // Load a StAX artifact processor
+
+            // Get the model QName
+            QName artifactType = getQName(attributes.get("qname"));
+
+            // Get the model class name
+            String modelTypeName = attributes.get("model");
+
+            // Get the model factory class name 
+            String factoryName = attributes.get("factory");
+
+            // Create a processor wrapper and register it
+            StAXAttributeProcessor processor =
+                new LazyStAXAttributeProcessor(artifactType, modelTypeName, factoryName,
+                                              processorDeclaration, extensionPoints, modelFactories, 
+                                              extensibleStAXAttributeProcessor, monitor);
+            addArtifactProcessor(processor);
+        }
+
+        loaded = true;
+    }
+
+    /**
+     * A wrapper around an Artifact processor class allowing lazy loading and
+     * initialization of artifact processors.
+     */
+    private static class LazyStAXAttributeProcessor implements StAXAttributeProcessor {
+
+        private ExtensionPointRegistry extensionPoints;
+        private QName artifactType;
+        private String modelTypeName;
+        private String factoryName;
+        private ServiceDeclaration processorDeclaration;
+        private StAXAttributeProcessor processor;
+        private Class<?> modelType;
+        private StAXAttributeProcessor<Object> extensionProcessor;
+        private Monitor monitor;
+
+        LazyStAXAttributeProcessor(QName artifactType,
+                                  String modelTypeName,
+                                  String factoryName,
+                                  ServiceDeclaration processorDeclaration,
+                                  ExtensionPointRegistry extensionPoints,
+                                  ModelFactoryExtensionPoint modelFactories,
+                                  StAXAttributeProcessor<Object> extensionProcessor,
+                                  Monitor monitor) {
+
+            this.extensionPoints = extensionPoints;
+            this.artifactType = artifactType;
+            this.modelTypeName = modelTypeName;
+            this.factoryName = factoryName;
+            this.processorDeclaration = processorDeclaration;
+            this.extensionProcessor = extensionProcessor;
+            this.monitor = monitor;
+        }
+
+        public QName getArtifactType() {
+            return artifactType;
+        }
+        
+        private void error(String message, Object model, Exception ex) {
+            if (monitor != null) {
+        	    Problem problem = new ProblemImpl(this.getClass().getName(), "contribution-validation-messages", Severity.ERROR, model, message, ex);
+        	    monitor.problem(problem);
+        	}        
+        }
+
+        @SuppressWarnings("unchecked")
+        private StAXAttributeProcessor getProcessor() {
+            if (processor == null) {
+                ModelFactoryExtensionPoint modelFactories = extensionPoints.getExtensionPoint(ModelFactoryExtensionPoint.class);
+
+                // Load and instantiate the processor class
+                try {
+                    Class<StAXAttributeProcessor> processorClass =
+                        (Class<StAXAttributeProcessor>)processorDeclaration.loadClass();
+                    try {
+                        Constructor<StAXAttributeProcessor> constructor =
+                            processorClass.getConstructor(ModelFactoryExtensionPoint.class, Monitor.class);
+                        processor = constructor.newInstance(modelFactories, monitor);
+                    } catch (NoSuchMethodException e) {
+                      try {
+                          Constructor<StAXAttributeProcessor> constructor =
+                              processorClass.getConstructor(ExtensionPointRegistry.class, Monitor.class);
+                          processor = constructor.newInstance(extensionPoints, monitor);
+                      } catch (NoSuchMethodException e1) {
+                        try {
+                            Constructor<StAXAttributeProcessor> constructor =
+                                processorClass.getConstructor(ModelFactoryExtensionPoint.class, StAXArtifactProcessor.class, Monitor.class);
+                            processor = constructor.newInstance(modelFactories, extensionProcessor, monitor);
+                        } catch (NoSuchMethodException e2) {
+                            try {
+                                Constructor<StAXAttributeProcessor> constructor =
+                                    processorClass.getConstructor(ExtensionPointRegistry.class, StAXArtifactProcessor.class, Monitor.class);
+                                processor = constructor.newInstance(extensionPoints, extensionProcessor, monitor);
+                            } catch (NoSuchMethodException e3) {
+                                try {
+                                    Constructor<StAXAttributeProcessor> constructor =
+                                        processorClass.getConstructor(ModelFactoryExtensionPoint.class);
+                                    processor = constructor.newInstance(modelFactories);
+                                } catch (NoSuchMethodException e4) {
+                                  try {
+                                      Constructor<StAXAttributeProcessor> constructor =
+                                          processorClass.getConstructor(ExtensionPointRegistry.class);
+                                      processor = constructor.newInstance(extensionPoints);
+                                  } catch (NoSuchMethodException e4a) {
+                                    try {
+                                        Constructor<StAXAttributeProcessor> constructor =
+                                            processorClass.getConstructor(ModelFactoryExtensionPoint.class, StAXArtifactProcessor.class);
+                                        processor = constructor.newInstance(modelFactories, extensionProcessor);
+                                    } catch (NoSuchMethodException e5) {
+                                        Constructor<StAXAttributeProcessor> constructor =
+                                            processorClass.getConstructor(ExtensionPointRegistry.class, StAXArtifactProcessor.class);
+                                        processor = constructor.newInstance(extensionPoints, extensionProcessor);
+                                    }
+                                  }
+                                }
+                            }
+                        }
+                      }
+                    }
+                } catch (Exception e) {
+                	IllegalStateException ie = new IllegalStateException(e);
+                	error("IllegalStateException", processor, ie);
+                    throw ie;
+                }
+
+            }
+            return processor;
+        }
+
+        public Object read(QName attributeName, XMLStreamReader inputSource) throws ContributionReadException, XMLStreamException {
+            return getProcessor().read(attributeName, inputSource);
+        }
+
+        @SuppressWarnings("unchecked")
+        public void write(Object model, XMLStreamWriter outputSource) throws ContributionWriteException, XMLStreamException {
+            getProcessor().write(model, outputSource);
+        }
+
+        public Class<?> getModelType() {
+            if (modelTypeName != null && modelType == null) {
+                try {
+                    modelType = processorDeclaration.loadClass(modelTypeName);
+                } catch (Exception e) {
+                	IllegalStateException ie = new IllegalStateException(e);
+                	error("IllegalStateException", processorDeclaration, ie);
+                    throw ie;
+                }
+            }
+            return modelType;
+        }
+
+        @SuppressWarnings("unchecked")
+        public void resolve(Object model, ModelResolver resolver) throws ContributionResolveException {
+            getProcessor().resolve(model, resolver);
+        }
+
+    }
+}
diff --git a/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/ExtensibleStAXAttributeProcessor.java b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/ExtensibleStAXAttributeProcessor.java
new file mode 100644
index 0000000000..3329f0bf1c
--- /dev/null
+++ b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/ExtensibleStAXAttributeProcessor.java
@@ -0,0 +1,224 @@
+/*
+ * 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.contribution.processor;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+import javax.xml.namespace.QName;
+import javax.xml.stream.Location;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLOutputFactory;
+import javax.xml.stream.XMLStreamConstants;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.XMLStreamReader;
+import javax.xml.stream.XMLStreamWriter;
+
+import org.apache.tuscany.sca.assembly.builder.impl.ProblemImpl;
+import org.apache.tuscany.sca.contribution.Constants;
+import org.apache.tuscany.sca.contribution.resolver.ModelResolver;
+import org.apache.tuscany.sca.contribution.service.ContributionReadException;
+import org.apache.tuscany.sca.contribution.service.ContributionResolveException;
+import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
+import org.apache.tuscany.sca.monitor.Monitor;
+import org.apache.tuscany.sca.monitor.Problem;
+import org.apache.tuscany.sca.monitor.Problem.Severity;
+
+/**
+ * Implementation of an extensible StAX attribute processor.
+ * 
+ * Takes a StAXAttributeProcessorExtensionPoint and delegates to the proper
+ * StAXAttributeProcessor by attribute QName
+ * 
+ * @version $Rev$ $Date$
+ */
+public class ExtensibleStAXAttributeProcessor
+    implements StAXAttributeProcessor<Object> {
+
+    private static final Logger logger = Logger.getLogger(ExtensibleStAXAttributeProcessor.class.getName()); 
+    
+    private static final QName UNKNOWN_ATTRIBUTE = new QName(Constants.SCA10_TUSCANY_NS, "unknown");
+    
+    private XMLInputFactory inputFactory;
+    private XMLOutputFactory outputFactory;
+    private StAXAttributeProcessorExtensionPoint processors;
+    private Monitor monitor;
+
+    /**
+     * Constructs a new ExtensibleStAXArtifactProcessor.
+     * @param processors
+     * @param inputFactory
+     * @param outputFactory
+     */
+    public ExtensibleStAXAttributeProcessor(StAXAttributeProcessorExtensionPoint processors, 
+    									   XMLInputFactory inputFactory, 
+    									   XMLOutputFactory outputFactory,
+    									   Monitor monitor) {
+        super();
+        this.processors = processors;
+        this.inputFactory = inputFactory;
+        this.outputFactory = outputFactory;
+        if (this.outputFactory != null) {
+            this.outputFactory.setProperty("javax.xml.stream.isRepairingNamespaces", Boolean.TRUE);
+        }
+        this.monitor = monitor;
+    }
+    
+    /**
+     * Report a warning.
+     * 
+     * @param problems
+     * @param message
+     * @param model
+     */
+     private void warning(String message, Object model, Object... messageParameters) {
+    	 if (monitor != null) {
+	        Problem problem = new ProblemImpl(this.getClass().getName(), "contribution-validation-messages", Severity.WARNING, model, message, (Object[])messageParameters);
+	        monitor.problem(problem);
+    	 }
+     }
+     
+     /**
+      * Report a error.
+      * 
+      * @param problems
+      * @param message
+      * @param model
+      */
+     private void error(String message, Object model, Object... messageParameters) {
+     	if (monitor != null) {
+ 	        Problem problem = new ProblemImpl(this.getClass().getName(), "contribution-validation-messages", Severity.ERROR, model, message, (Object[])messageParameters);
+ 	        monitor.problem(problem);
+     	}
+     }
+    
+    /**
+     * Report a exception.
+     * 
+     * @param problems
+     * @param message
+     * @param model
+     */
+     private void error(String message, Object model, Exception ex) {
+    	 if (monitor != null) {
+    		 Problem problem = new ProblemImpl(this.getClass().getName(), "contribution-validation-messages", Severity.ERROR, model, message, ex);
+    	     monitor.problem(problem);
+    	 }        
+     }
+
+
+    public Object read(QName attributeName, XMLStreamReader source) throws ContributionReadException, XMLStreamException {
+        
+        // Delegate to the processor associated with the attribute QName
+        int event = source.getEventType();
+        if (event == XMLStreamConstants.START_DOCUMENT) {
+            source.nextTag();
+        }
+
+        StAXAttributeProcessor<?> processor = null;
+        
+        //lookup for registered attribute processors
+        processor = (StAXAttributeProcessor<?>)processors.getProcessor(attributeName);
+        if (processor == null) {
+        	Location location = source.getLocation();
+            if (logger.isLoggable(Level.WARNING)) {                
+                logger.warning("Attribute " + attributeName + " cannot be processed. (" + location + ")");
+            }
+            warning("AttributeCannotBeProcessed", processors, attributeName, location);            
+        } else {
+        	return processor.read(attributeName, source);
+        }
+        
+        return processor == null ? null : processor.read(attributeName, source);
+    }
+    
+    @SuppressWarnings("unchecked")
+    public void write(Object model, XMLStreamWriter outputSource) throws ContributionWriteException, XMLStreamException {
+        
+    	if(model == null) {
+    		return;
+    	}
+    	
+        // Delegate to the processor associated with the model type
+    	StAXAttributeProcessor processor = processors.getProcessor(model.getClass());
+    	if(processor == null) {
+    		if (logger.isLoggable(Level.WARNING)) {
+    			logger.warning("No StAX processor is configured to handle " + model.getClass());
+    		}
+    		warning("NoStaxProcessor", processors, model.getClass());    		
+    	} else {
+    		processor.write(model, outputSource);
+    		return;
+    	}
+    }
+    
+    
+    
+    @SuppressWarnings("unchecked")
+    public void resolve(Object model, ModelResolver resolver) throws ContributionResolveException {
+
+        // Delegate to the processor associated with the model type
+        if (model != null) {
+        	StAXAttributeProcessor processor = processors.getProcessor(model.getClass());
+            if (processor != null) {
+                processor.resolve(model, resolver);
+            }
+        }
+    }
+    
+    /**
+     * Read a model from an InputStream.
+     * @param is The artifact InputStream
+     * @param type Model type
+     * @return The model
+     * @throws ContributionReadException
+     */
+    public <M> M read(InputStream is, Class<M> type) throws ContributionReadException {
+        return null;
+    }
+
+    /**
+     * Write a model to an OutputStream.
+     * @param model
+     * @param os
+     * @throws ContributionWriteException
+     */
+    public void write(Object model, OutputStream os) throws ContributionWriteException {
+        try {
+            XMLStreamWriter writer = outputFactory.createXMLStreamWriter(os);
+            write(model, writer);
+            writer.flush();
+            writer.close();
+        } catch (XMLStreamException e) {
+        	ContributionWriteException cw = new ContributionWriteException(e);
+        	error("ContributionWriteException", outputFactory, cw);
+            throw cw;
+        }
+    }
+
+    public QName getArtifactType() {
+        return null;
+    }
+    
+    public Class<Object> getModelType() {
+        return null;
+    }
+}
diff --git a/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/StAXAttributeProcessor.java b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/StAXAttributeProcessor.java
new file mode 100644
index 0000000000..e8edb743a4
--- /dev/null
+++ b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/StAXAttributeProcessor.java
@@ -0,0 +1,63 @@
+/*
+ * 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.contribution.processor;
+
+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.service.ContributionReadException;
+import org.apache.tuscany.sca.contribution.service.ContributionWriteException;
+
+
+/**
+ * An artifact processor that can read attributes from a StAX XMLStreamReader.
+ * 
+ * @version $Rev$ $Date$
+ */
+public interface StAXAttributeProcessor<M> extends ArtifactProcessor<M>{
+
+    /**
+     * Reads a model from an XMLStreamReader.
+     * 
+     * @param reader The XMLStreamReader
+     * @return A model representation of the input.
+     */
+    M read(QName attributeName, XMLStreamReader reader) throws ContributionReadException, XMLStreamException;
+    
+    /**
+     * Writes a model to an XMLStreamWriter.
+     * 
+     * @param model A model representing the source
+     * @param writer The XML stream writer
+     * @throws ContributionWriteException
+     * @throws XMLStreamException
+     */
+    void write(M model, XMLStreamWriter writer) throws ContributionWriteException, XMLStreamException;
+    
+    /**
+     * Returns the type of artifact handled by this artifact processor.
+     *  
+     * @return The type of artifact handled by this artifact processor
+     */
+    QName getArtifactType();
+
+}
diff --git a/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/StAXAttributeProcessorExtensionPoint.java b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/StAXAttributeProcessorExtensionPoint.java
new file mode 100644
index 0000000000..ebad243c1c
--- /dev/null
+++ b/java/sca/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/processor/StAXAttributeProcessorExtensionPoint.java
@@ -0,0 +1,29 @@
+/*
+ * 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.contribution.processor;
+
+/**
+ * An extension point for StAX artifact processors.
+ * 
+ * @version $Rev$ $Date$
+ */
+public interface StAXAttributeProcessorExtensionPoint extends 
+    ArtifactProcessorExtensionPoint<StAXAttributeProcessor> {
+
+}
diff --git a/java/sca/modules/contribution/src/main/resources/META-INF/services/org.apache.tuscany.sca.contribution.processor.StAXAttributeProcessorExtensionPoint b/java/sca/modules/contribution/src/main/resources/META-INF/services/org.apache.tuscany.sca.contribution.processor.StAXAttributeProcessorExtensionPoint
new file mode 100644
index 0000000000..607725bcfe
--- /dev/null
+++ b/java/sca/modules/contribution/src/main/resources/META-INF/services/org.apache.tuscany.sca.contribution.processor.StAXAttributeProcessorExtensionPoint
@@ -0,0 +1,18 @@
+# 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. 

+

+org.apache.tuscany.sca.contribution.processor.DefaultStAXAttributeProcessorExtensionPoint