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

6 files changed, 384 insertions, 16 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>