Create 2.0-M2 release branch

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@757361 13f79535-47bb-0310-9956-ffa450edef68

18 files changed, 1602 insertions, 0 deletions

diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultExtensionPointRegistry.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultExtensionPointRegistry.java
new file mode 100644
index 0000000000..12979723b1
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultExtensionPointRegistry.java
@@ -0,0 +1,186 @@
+/*
+ * 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.core;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Modifier;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+import org.apache.tuscany.sca.extensibility.ServiceDiscovery;
+
+/**
+ * Default implementation of a registry to hold all the Tuscany core extension
+ * points. As the point of contact for all extension artifacts this registry
+ * allows loaded extensions to find all other parts of the system and register
+ * themselves appropriately.
+ *
+ * @version $Rev$ $Date$
+ */
+public class DefaultExtensionPointRegistry implements ExtensionPointRegistry {
+    private Map<Class<?>, Object> extensionPoints = new HashMap<Class<?>, Object>();
+    
+    /**
+     * Constructs a new registry. 
+     */
+    public DefaultExtensionPointRegistry() {
+    }
+
+    /**
+     * Add an extension point to the registry. This default implementation
+     * stores extensions against the interfaces that they implement.
+     *
+     * @param extensionPoint The instance of the extension point
+     *
+     * @throws IllegalArgumentException if extensionPoint is null
+     */
+    public void addExtensionPoint(Object extensionPoint) {
+        if (extensionPoint == null) {
+            throw new IllegalArgumentException("Cannot register null as an ExtensionPoint");
+        }
+
+        Set<Class<?>> interfaces = getAllInterfaces(extensionPoint.getClass());
+        for (Class<?> i : interfaces) {
+            extensionPoints.put(i, extensionPoint);
+        }
+    }
+    
+    private Constructor<?> getConstructor(Constructor<?>[] constructors, Class<?>[] paramTypes) {
+        for (Constructor<?> c : constructors) {
+            Class<?>[] types = c.getParameterTypes();
+            if (c.getParameterTypes().length == paramTypes.length) {
+                boolean found = true;
+                for (int i = 0; i < types.length; i++) {
+                    if (types[i] != paramTypes[i]) {
+                        found = false;
+                        break;
+                    }
+                }
+                if (found) {
+                    return c;
+                }
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Get the extension point by the interface that it implements
+     *
+     * @param extensionPointType The lookup key (extension point interface)
+     * @return The instance of the extension point
+     *
+     * @throws IllegalArgumentException if extensionPointType is null
+     */
+    public <T> T getExtensionPoint(Class<T> extensionPointType) {
+        if (extensionPointType == null) {
+            throw new IllegalArgumentException("Cannot lookup ExtensionPoint of type null");
+        }
+
+        Object extensionPoint = extensionPoints.get(extensionPointType);
+        if (extensionPoint == null) {
+            
+            // Dynamically load an extension point class declared under META-INF/services           
+            try {
+                ServiceDeclaration extensionPointDeclaration = ServiceDiscovery.getInstance().getFirstServiceDeclaration(extensionPointType.getName());
+                if (extensionPointDeclaration != null) {
+                    Class<?> extensionPointClass = extensionPointDeclaration.loadClass();
+                    
+                    // Construct the extension point
+                    Constructor<?>[] constructors = extensionPointClass.getConstructors();
+                    Constructor<?> constructor = getConstructor(constructors, new Class<?>[] {ExtensionPointRegistry.class});
+                    if (constructor != null) {
+                        extensionPoint = constructor.newInstance(this);
+                    } else {
+                        constructor = getConstructor(constructors, new Class<?>[] {});
+                        if (constructor != null) {
+                            extensionPoint = constructor.newInstance();
+                        } else {
+                            throw new IllegalArgumentException(
+                                                               "No valid constructor is found for " + extensionPointClass);
+                        }
+                    }
+                   
+                    // Cache the loaded extension point
+                    addExtensionPoint(extensionPoint);
+                }
+            } catch (InvocationTargetException e) {
+                throw new IllegalArgumentException(e);
+            } catch (IOException e) {
+                throw new IllegalArgumentException(e);
+            } catch (ClassNotFoundException e) {
+                throw new IllegalArgumentException(e);
+            } catch (InstantiationException e) {
+                throw new IllegalArgumentException(e);
+            } catch (IllegalAccessException e) {
+                throw new IllegalArgumentException(e);
+            }
+        }
+        return extensionPointType.cast(extensionPoint);
+    }
+
+    /**
+     * Remove an extension point based on the interface that it implements
+     *
+     * @param extensionPoint The extension point to remove
+     *
+     * @throws IllegalArgumentException if extensionPoint is null
+     */
+    public void removeExtensionPoint(Object extensionPoint) {
+        if (extensionPoint == null) {
+            throw new IllegalArgumentException("Cannot remove null as an ExtensionPoint");
+        }
+
+        Set<Class<?>> interfaces = getAllInterfaces(extensionPoint.getClass());
+        for (Class<?> i : interfaces) {
+            extensionPoints.remove(i);
+        }
+    }
+
+    /**
+     * Returns the set of interfaces implemented by the given class and its
+     * ancestors or a blank set if none
+     */
+    private static Set<Class<?>> getAllInterfaces(Class<?> clazz) {
+        Set<Class<?>> implemented = new HashSet<Class<?>>();
+        getAllInterfaces(clazz, implemented);
+        return implemented;
+    }
+
+    private static void getAllInterfaces(Class<?> clazz, Set<Class<?>> implemented) {
+        Class<?>[] interfaces = clazz.getInterfaces();
+        for (Class<?> interfaze : interfaces) {
+            if (Modifier.isPublic(interfaze.getModifiers())) {
+                implemented.add(interfaze);
+            }
+        }
+        Class<?> superClass = clazz.getSuperclass();
+        // Object has no superclass so check for null
+        if (superClass != null && !superClass.equals(Object.class)) {
+            getAllInterfaces(superClass, implemented);
+        }
+    }
+
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultFactoryExtensionPoint.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultFactoryExtensionPoint.java
new file mode 100644
index 0000000000..80c4e2b69d
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultFactoryExtensionPoint.java
@@ -0,0 +1,174 @@
+/*
+ * 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.core;
+
+import java.lang.reflect.Constructor;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.util.HashMap;
+
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+import org.apache.tuscany.sca.extensibility.ServiceDiscovery;
+
+
+
+/**
+ * Default implementation of a model factory extension point.
+ *
+ * @version $Rev$ $Date$
+ */
+public class DefaultFactoryExtensionPoint implements FactoryExtensionPoint {
+    private ExtensionPointRegistry extensionPointRegistry;
+    private HashMap<Class<?>, Object> factories = new HashMap<Class<?>, Object>();
+    
+    /**
+     * Constructs a new DefaultModelFactoryExtensionPoint.
+     */
+    public DefaultFactoryExtensionPoint(ExtensionPointRegistry extensionPointRegistry) {
+        this.extensionPointRegistry = extensionPointRegistry;
+    }
+
+    /**
+     * Add a model factory extension.
+     * 
+     * @param factory The factory to add
+     */
+    public void addFactory(Object factory) {
+        Class<?>[] interfaces = factory.getClass().getInterfaces();
+        if (interfaces.length == 0) {
+            Class<?> sc = factory.getClass().getSuperclass();
+            if (sc != Object.class) {
+                factories.put(sc, factory);
+            }
+        } else {
+            for (int i = 0; i<interfaces.length; i++) {
+                factories.put(interfaces[i], factory);
+            }
+        }
+    }
+
+    /**
+     * Remove a model factory.
+     *  
+     * @param factory The factory to remove
+     */
+    public void removeFactory(Object factory) {
+        Class<?>[] interfaces = factory.getClass().getInterfaces();
+        if (interfaces.length == 0) {
+            Class<?> sc = factory.getClass().getSuperclass();
+            if (sc != Object.class) {
+                factories.remove(sc);
+            }
+        } else {
+            for (int i = 0; i<interfaces.length; i++) {
+                factories.remove(interfaces[i]);
+            }
+        }
+    }
+    
+    private ClassLoader setContextClassLoader(final ClassLoader classLoader) {
+        return AccessController.doPrivileged(new PrivilegedAction<ClassLoader>() {
+            public ClassLoader run() {
+                ClassLoader tccl = Thread.currentThread().getContextClassLoader();
+                if (classLoader != null) {
+                    Thread.currentThread().setContextClassLoader(classLoader);
+                }
+                return tccl;
+            }
+        });
+    }
+
+    /**
+     * Get a factory implementing the given interface.
+     * @param factoryInterface The lookup key (factory interface)
+     * @return The factory
+     */    
+    public <T> T getFactory(Class<T> factoryInterface) {
+        Object factory = factories.get(factoryInterface);
+        if (factory == null) {
+
+            // Dynamically load a factory class declared under META-INF/services 
+            try {
+                ServiceDeclaration factoryDeclaration =
+                    ServiceDiscovery.getInstance().getFirstServiceDeclaration(factoryInterface.getName());
+                if (factoryDeclaration != null) {
+                    Class<?> factoryClass = factoryDeclaration.loadClass();
+                    try {
+                        
+                        // Default empty constructor
+                        Constructor<?> constructor = factoryClass.getConstructor();
+                        factory = constructor.newInstance();
+                    } catch (NoSuchMethodException e) {
+                        try {
+
+                            // Constructor taking the model factory extension point
+                            Constructor<?> constructor = factoryClass.getConstructor(FactoryExtensionPoint.class);
+                            factory = constructor.newInstance(this);
+                        } catch (NoSuchMethodException e1) {
+
+                            // Constructor taking the extension point registry
+                            Constructor<?> constructor = factoryClass.getConstructor(ExtensionPointRegistry.class);
+                            factory = constructor.newInstance(extensionPointRegistry);
+                        }
+                    }
+
+                    // Cache the loaded factory
+                    factories.put(factoryInterface, factory);
+                    
+                    return  factoryInterface.cast(factory);
+                    
+                } else {
+                    
+                    // If the input interface is an abstract class
+                    if (!factoryInterface.isInterface() && Modifier.isAbstract(factoryInterface.getModifiers())) {
+                        Method newInstanceMethod = factoryInterface.getDeclaredMethod("newInstance");
+                        ClassLoader tccl = setContextClassLoader(factoryInterface.getClassLoader());
+                        try {
+                            
+                            // Create a new instance
+                            factory = newInstanceMethod.invoke(null);
+                            
+                            // Cache the factory
+                            factories.put(factoryInterface, factory);
+                            
+                            return  factoryInterface.cast(factory);
+                        } catch (Exception e) {
+                            // Sorry no factory found
+                            return null;
+                        } finally {
+                            setContextClassLoader(tccl);
+                        }
+                    } else {
+                        
+                        // Sorry no factory found
+                        return null;
+                    }
+                }
+            } catch (Exception e) {
+                throw new IllegalArgumentException(e);
+            }
+        } else {
+            return factoryInterface.cast(factory);
+        }
+    }
+
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultModuleActivatorExtensionPoint.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultModuleActivatorExtensionPoint.java
new file mode 100644
index 0000000000..f5aced9b50
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultModuleActivatorExtensionPoint.java
@@ -0,0 +1,92 @@
+/*
+ * 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.core;
+
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Set;
+
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+import org.apache.tuscany.sca.extensibility.ServiceDiscovery;
+
+/**
+ * Default implementation of an extension point to hold Tuscany module activators.
+ *
+ * @version $Rev$ $Date$
+ */
+public class DefaultModuleActivatorExtensionPoint implements ModuleActivatorExtensionPoint {
+    private List<ModuleActivator> activators = new ArrayList<ModuleActivator>();
+    private boolean loadedActivators;
+    
+    /**
+     * Constructs a new extension point. 
+     */
+    public DefaultModuleActivatorExtensionPoint() {
+    }
+
+    public void addModuleActivator(ModuleActivator activator) {
+        activators.add(activator);
+    }
+    
+    public List<ModuleActivator> getModuleActivators() {
+        loadModuleActivators();
+        return activators;
+    }
+    
+    public void removeModuleActivator(Object activator) {
+        activators.remove(activator);
+    }
+
+    /**
+     * Dynamically load module activators declared under META-INF/services
+     */
+    private synchronized void loadModuleActivators() {
+        if (loadedActivators)
+            return;
+
+        // Get the activator service declarations
+        Set<ServiceDeclaration> activatorDeclarations; 
+        try {
+            activatorDeclarations = ServiceDiscovery.getInstance().getServiceDeclarations(ModuleActivator.class.getName());
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        
+        // Load and instantiate module activators
+        for (ServiceDeclaration activatorDeclaration: activatorDeclarations) {
+            ModuleActivator activator;
+            try {
+                Class<ModuleActivator> activatorClass = (Class<ModuleActivator>)activatorDeclaration.loadClass();
+                activator = activatorClass.newInstance();
+            } catch (ClassNotFoundException e) {
+                throw new IllegalArgumentException(e);
+            } catch (InstantiationException e) {
+                throw new IllegalArgumentException(e);
+            } catch (IllegalAccessException e) {
+                throw new IllegalArgumentException(e);
+            }
+            addModuleActivator(activator);
+        }
+        
+        loadedActivators = true;
+    }
+
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultUtilityExtensionPoint.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultUtilityExtensionPoint.java
new file mode 100644
index 0000000000..fd85c5afa0
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultUtilityExtensionPoint.java
@@ -0,0 +1,192 @@
+/*
+ * 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.core;
+
+import java.io.IOException;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Modifier;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+import org.apache.tuscany.sca.extensibility.ServiceDiscovery;
+
+/**
+ * Default implementation of an extension point to hold Tuscany utility utilities.
+ *
+ * @version $Rev$ $Date$
+ */
+public class DefaultUtilityExtensionPoint implements UtilityExtensionPoint {
+    private Map<Class<?>, Object> utilities = new ConcurrentHashMap<Class<?>, Object>();
+    
+    private ExtensionPointRegistry extensionPoints;
+    
+    /**
+     * Constructs a new extension point. 
+     */
+    public DefaultUtilityExtensionPoint(ExtensionPointRegistry extensionPoints) {
+        this.extensionPoints = extensionPoints;
+    }
+
+    /**
+     * Add a utility to the extension point. This default implementation
+     * stores utilities against the interfaces that they implement.
+     *
+     * @param utility The instance of the utility
+     *
+     * @throws IllegalArgumentException if utility is null
+     */
+    public void addUtility(Object utility) {
+        if (utility == null) {
+            throw new IllegalArgumentException("Cannot register null as a Service");
+        }
+
+        Set<Class<?>> interfaces = getAllInterfaces(utility.getClass());
+        for (Class<?> i : interfaces) {
+            utilities.put(i, utility);
+        }
+    }
+    
+    private Constructor<?> getConstructor(Constructor<?>[] constructors, Class<?>[] paramTypes) {
+        for (Constructor<?> c : constructors) {
+            Class<?>[] types = c.getParameterTypes();
+            if (c.getParameterTypes().length == paramTypes.length) {
+                boolean found = true;
+                for (int i = 0; i < types.length; i++) {
+                    if (types[i] != paramTypes[i]) {
+                        found = false;
+                        break;
+                    }
+                }
+                if (found) {
+                    return c;
+                }
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Get the utility by the interface that it implements
+     *
+     * @param utilityType The lookup key (utility interface)
+     * @return The instance of the utility
+     *
+     * @throws IllegalArgumentException if utilityType is null
+     */
+    public <T> T getUtility(Class<T> utilityType) {
+        return getUtility(utilityType, false);
+    }
+
+    /**
+     * Remove a utility based on the interface that it implements
+     *
+     * @param utility The utility to remove
+     *
+     * @throws IllegalArgumentException if utility is null
+     */
+    public void removeUtility(Object utility) {
+        if (utility == null) {
+            throw new IllegalArgumentException("Cannot remove null as a Service");
+        }
+
+        Set<Class<?>> interfaces = getAllInterfaces(utility.getClass());
+        for (Class<?> i : interfaces) {
+            utilities.remove(i);
+        }
+    }
+
+    /**
+     * Returns the set of interfaces implemented by the given class and its
+     * ancestors or a blank set if none
+     */
+    private static Set<Class<?>> getAllInterfaces(Class<?> clazz) {
+        Set<Class<?>> implemented = new HashSet<Class<?>>();
+        getAllInterfaces(clazz, implemented);
+        return implemented;
+    }
+
+    private static void getAllInterfaces(Class<?> clazz, Set<Class<?>> implemented) {
+        Class<?>[] interfaces = clazz.getInterfaces();
+        for (Class<?> interfaze : interfaces) {
+            if (Modifier.isPublic(interfaze.getModifiers())) {
+                implemented.add(interfaze);
+            }
+        }
+        Class<?> superClass = clazz.getSuperclass();
+        // Object has no superclass so check for null
+        if (superClass != null && !superClass.equals(Object.class)) {
+            getAllInterfaces(superClass, implemented);
+        }
+    }
+
+    public <T> T getUtility(Class<T> utilityType, boolean newInstance) {
+        if (utilityType == null) {
+            throw new IllegalArgumentException("Cannot lookup Service of type null");
+        }
+
+        Object utility = null;
+        if (!newInstance) {
+            utility = utilities.get(utilityType);
+        }
+        if (utility == null) {
+            
+            // Dynamically load a utility class declared under META-INF/services/"utilityType"           
+            try {
+                ServiceDeclaration utilityDeclaration =ServiceDiscovery.getInstance().getFirstServiceDeclaration(utilityType.getName());
+                if (utilityDeclaration != null) {
+                    Class<?> utilityClass = utilityDeclaration.loadClass();
+                    
+                    // Construct the utility
+                    Constructor<?>[] constructors = utilityClass.getConstructors();
+                    Constructor<?> constructor = getConstructor(constructors, new Class<?>[] {ExtensionPointRegistry.class});
+                    if (constructor != null) {
+                        utility = constructor.newInstance(extensionPoints);
+                    } else {
+                        constructor = getConstructor(constructors, new Class<?>[] {});
+                        if (constructor != null) {
+                            utility = constructor.newInstance();
+                        } else {
+                            throw new IllegalArgumentException(
+                                                               "No valid constructor is found for " + utilityClass);
+                        }
+                    }
+                   
+                    // Cache the loaded utility
+                    addUtility(utility);
+                }
+            } catch (InvocationTargetException e) {
+                throw new IllegalArgumentException(e);
+            } catch (IOException e) {
+                throw new IllegalArgumentException(e);
+            } catch (ClassNotFoundException e) {
+                throw new IllegalArgumentException(e);
+            } catch (InstantiationException e) {
+                throw new IllegalArgumentException(e);
+            } catch (IllegalAccessException e) {
+                throw new IllegalArgumentException(e);
+            }
+        }
+        return utilityType.cast(utility);    }
+
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/ExtensionPointRegistry.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/ExtensionPointRegistry.java
new file mode 100644
index 0000000000..f2f67b2d52
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/ExtensionPointRegistry.java
@@ -0,0 +1,56 @@
+/*
+ * 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.core;
+
+
+/**
+ * The registry for the Tuscany core extension points. As the point of contact
+ * for all extension artifacts this registry allows loaded extensions to find
+ * all other parts of the system and register themselves appropriately.
+ *
+ * @version $Rev$ $Date$
+ */
+public interface ExtensionPointRegistry {
+
+    /**
+     * Add an extension point to the registry
+     * @param extensionPoint The instance of the extension point
+     *
+     * @throws IllegalArgumentException if extensionPoint is null
+     */
+    void addExtensionPoint(Object extensionPoint);
+
+    /**
+     * Get the extension point by the interface
+     * @param extensionPointType The lookup key (extension point interface)
+     * @return The instance of the extension point
+     *
+     * @throws IllegalArgumentException if extensionPointType is null
+     */
+    <T> T getExtensionPoint(Class<T> extensionPointType);
+
+    /**
+     * Remove an extension point
+     * @param extensionPoint The extension point to remove
+     *
+     * @throws IllegalArgumentException if extensionPoint is null
+     */
+    void removeExtensionPoint(Object extensionPoint);
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/FactoryExtensionPoint.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/FactoryExtensionPoint.java
new file mode 100644
index 0000000000..4d38cb8afe
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/FactoryExtensionPoint.java
@@ -0,0 +1,54 @@
+/*
+ * 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.core;
+
+/**
+ * An extension point for model factories. Model factories are provided to 
+ * abstract the classes that represent artifacts in the assembly model away
+ * from their creation mechanism. When the runtime needs to extend the model
+ * as it reads in contributed artifacts it looks up the factory for the 
+ * artifact required in this registry
+ *
+ * @version $Rev$ $Date$
+ */
+public interface FactoryExtensionPoint {
+    
+    /**
+     * Add a model factory extension.
+     * 
+     * @param factory The factory to add
+     */
+    void addFactory(Object factory);
+    
+    /**
+     * Remove a model factory extension.
+     *  
+     * @param factory The factory to remove
+     */
+    void removeFactory(Object factory); 
+    
+    /**
+     * Get a factory implementing the given interface.
+     * @param factoryInterface the lookup key (factory interface)
+     * @return The factory
+     */
+    <T> T getFactory(Class<T> factoryInterface);
+
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/ModuleActivator.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/ModuleActivator.java
new file mode 100644
index 0000000000..dbfd0dcd90
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/ModuleActivator.java
@@ -0,0 +1,60 @@
+/*
+ * 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.core;
+
+
+/**
+ * ModuleActivator represents a module that plugs into the Tuscany system. Each 
+ * module should provide an implementation of this interface and register the 
+ * ModuleActivator implementation class by defining a file named 
+ * 
+ * "META-INF/services/org.apache.tuscany.core.ModuleActivator"
+ * 
+ * The content of the file is the class name of the ModuleActivator implementation. 
+ * The implementation class must have a no-arg constructor. The same instance 
+ * will be used to invoke all the methods during different phases of the module 
+ * activation. Note that the start and stop methods defined by this interface
+ * take a reference to the Tuscany SCA runtime ExtensionPointRegistry. This 
+ * gives the ModuleActivator the opportunity to add extension points to the
+ * registry as it is requested to start up and remove them when it is requested
+ * to shut down.
+ * 
+ * @version $Rev$ $Date$
+ */
+public interface ModuleActivator {
+
+    /**
+     * This method is invoked when the module is started by the Tuscany system.
+     * It can be used by this module to register extensions against extension
+     * points.
+     * 
+     * @param registry The extension point registry
+     */
+    void start(ExtensionPointRegistry registry);
+
+    /**
+     * This method is invoked when the module is stopped by the Tuscany system.
+     * It can be used by this module to unregister extensions against the
+     * extension points.
+     * 
+     * @param registry The extension point registry
+     */
+    void stop(ExtensionPointRegistry registry);
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/ModuleActivatorExtensionPoint.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/ModuleActivatorExtensionPoint.java
new file mode 100644
index 0000000000..ec0f12b8ba
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/ModuleActivatorExtensionPoint.java
@@ -0,0 +1,53 @@
+/*
+ * 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.core;
+
+import java.util.List;
+
+
+/**
+ * The extension point for the Tuscany module activator extensions.
+ *
+ * @version $Rev$ $Date$
+ */
+public interface ModuleActivatorExtensionPoint {
+
+    /**
+     * Add a module activator extension to the extension point
+     * @param activator The instance of the module activator
+     *
+     * @throws IllegalArgumentException if activator is null
+     */
+    void addModuleActivator(ModuleActivator activator);
+
+    /**
+     * Returns the module activator extensions.
+     * @return The module activator extensions
+     */
+    List<ModuleActivator> getModuleActivators();
+
+    /**
+     * Remove a module activator
+     * @param activator The module activator to remove
+     *
+     * @throws IllegalArgumentException if activator is null
+     */
+    void removeModuleActivator(Object activator);
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/UtilityExtensionPoint.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/UtilityExtensionPoint.java
new file mode 100644
index 0000000000..9804234850
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/UtilityExtensionPoint.java
@@ -0,0 +1,64 @@
+/*
+ * 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.core;
+
+
+/**
+ * The extension point for the Tuscany core utility extensions.
+ *
+ * @version $Rev$ $Date$
+ */
+public interface UtilityExtensionPoint {
+
+    /**
+     * Add a utility to the extension point
+     * @param utility The instance of the utility
+     *
+     * @throws IllegalArgumentException if utility is null
+     */
+    void addUtility(Object utility);
+
+    /**
+     * Get the utility by the interface
+     * @param utilityType The lookup key (utility interface)
+     * @return The instance of the utility
+     *
+     * @throws IllegalArgumentException if utilityType is null
+     */
+    <T> T getUtility(Class<T> utilityType);
+
+    /**
+     * Get a new instance of the utility by the interface
+     * @param utilityType The lookup key (utility interface)
+     * @param newInstance A new instance is required
+     * @return The instance of the utility
+     *
+     * @throws IllegalArgumentException if utilityType is null
+     */
+    <T> T getUtility(Class<T> utilityType, boolean newInstance);
+    
+    /**
+     * Remove a utility
+     * @param utility The utility to remove
+     *
+     * @throws IllegalArgumentException if utility is null
+     */
+    void removeUtility(Object utility);
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ContextClassLoaderServiceDiscoverer.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ContextClassLoaderServiceDiscoverer.java
new file mode 100644
index 0000000000..41764f35b9
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ContextClassLoaderServiceDiscoverer.java
@@ -0,0 +1,272 @@
+/*
+ * 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.extensibility;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.lang.ref.WeakReference;
+import java.net.URL;
+import java.net.URLConnection;
+import java.security.AccessController;
+import java.security.PrivilegedAction;
+import java.security.PrivilegedActionException;
+import java.security.PrivilegedExceptionAction;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+import java.util.StringTokenizer;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/**
+ * A ServiceDiscoverer that find META-INF/services/... using the Context ClassLoader.
+ *
+ * @version $Rev$ $Date$
+ */
+public class ContextClassLoaderServiceDiscoverer implements ServiceDiscoverer {
+    private static final Logger logger = Logger.getLogger(ContextClassLoaderServiceDiscoverer.class.getName());
+
+    public class ServiceDeclarationImpl implements ServiceDeclaration {
+        private URL url;
+        private String className;
+        private Class<?> javaClass;
+        private Map<String, String> attributes;
+
+        public ServiceDeclarationImpl(URL url, String className, Map<String, String> attributes) {
+            super();
+            this.url = url;
+            this.className = className;
+            this.attributes = attributes;
+        }
+
+        public Map<String, String> getAttributes() {
+            return attributes;
+        }
+
+        public String getClassName() {
+            return className;
+        }
+
+        public URL getLocation() {
+            return url;
+        }
+
+        public Class<?> loadClass() throws ClassNotFoundException {
+            if (className == null) {
+                return null;
+            }
+            if (javaClass == null) {
+                javaClass = loadClass(className);
+            }
+            return javaClass;
+        }
+
+        public Class<?> loadClass(String className) throws ClassNotFoundException {
+            return Class.forName(className, false, classLoaderReference.get());
+        }
+
+        @Override
+        public String toString() {
+            StringBuffer sb = new StringBuffer();
+            sb.append("ClassLoader: ").append(classLoaderReference.get());
+            sb.append(" Attributes: ").append(attributes);
+            return sb.toString();
+        }
+
+        public URL getResource(final String name) {
+            return AccessController.doPrivileged(new PrivilegedAction<URL>() {
+                public URL run() {
+                    return classLoaderReference.get().getResource(name);
+                }
+            });
+        }
+
+    }
+
+    private WeakReference<ClassLoader> classLoaderReference;
+
+    public ContextClassLoaderServiceDiscoverer() {
+        ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
+        this.classLoaderReference = new WeakReference<ClassLoader>(classLoader);
+    }
+
+    private List<URL> getResources(final String name) throws IOException {
+        try {
+            return AccessController.doPrivileged(new PrivilegedExceptionAction<List<URL>>() {
+                public List<URL> run() throws IOException {
+                    List<URL> urls = Collections.list(classLoaderReference.get().getResources(name));
+                    return urls;
+                }
+            });
+        } catch (PrivilegedActionException e) {
+            throw (IOException)e.getException();
+        }
+    }
+
+    /**
+     * Parse a service declaration in the form class;attr=value,attr=value and
+     * return a map of attributes
+     * 
+     * @param declaration
+     * @return a map of attributes
+     */
+    private static Map<String, String> parseServiceDeclaration(String declaration) {
+        Map<String, String> attributes = new HashMap<String, String>();
+        int index = declaration.indexOf(';');
+        if (index != -1) {
+            attributes.put("class", declaration.substring(0, index).trim());
+            declaration = declaration.substring(index);
+        } else {
+            int j = declaration.indexOf('=');
+            if (j == -1) {
+                attributes.put("class", declaration.trim());
+                return attributes;
+            } else {
+                declaration = ";" + declaration;
+            }
+        }
+        StringTokenizer tokens = new StringTokenizer(declaration);
+        for (; tokens.hasMoreTokens();) {
+            String key = tokens.nextToken("=").substring(1).trim();
+            if (key == null)
+                break;
+            String value = tokens.nextToken(",").substring(1).trim();
+            if (value == null)
+                break;
+            attributes.put(key, value);
+        }
+        return attributes;
+    }
+
+    public ServiceDeclaration getFirstServiceDeclaration(String name) throws IOException {
+        Set<ServiceDeclaration> declarations = getServiceDeclarations(name);
+        if (declarations.isEmpty()) {
+            return null;
+        } else {
+            return declarations.iterator().next();
+        }
+    }
+
+    public Set<ServiceDeclaration> getServiceDeclarations(String serviceName) {
+        Set<ServiceDeclaration> descriptors = new HashSet<ServiceDeclaration>();
+
+        // http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/xpath/XPathFactory.html
+        boolean isPropertyFile = "javax.xml.xpath.XPathFactory".equals(serviceName);
+        String name = "META-INF/services/" + serviceName;
+        boolean debug = logger.isLoggable(Level.FINE);
+        try {
+            for (final URL url : getResources(name)) {
+                if (debug) {
+                    logger.fine("Reading service provider file: " + url.toExternalForm());
+                }
+
+                // Allow privileged access to open URL stream. Add FilePermission to added to security
+                // policy file.
+                InputStream is;
+                try {
+                    is = AccessController.doPrivileged(new PrivilegedExceptionAction<InputStream>() {
+                        public InputStream run() throws IOException {
+                            URLConnection connection = url.openConnection();
+                            // TUSCANY-2539
+                            // Don't cache connections by default to stop Tuscany locking contribution jar files
+                            // done here as this is one of the first places we open a stream and the only way to 
+                            // set the default is to set it on an instance of URLConnection
+                            connection.setDefaultUseCaches(false);                            
+                            connection.setUseCaches(false);
+                            return url.openStream();
+                        }
+                    });
+                } catch (PrivilegedActionException e) {
+                    throw (IOException)e.getException();
+                }
+                if (isPropertyFile) {
+                    // Load as a property file
+                    Properties props = new Properties();
+                    props.load(is);
+                    is.close();
+                    for (Map.Entry<Object, Object> e : props.entrySet()) {
+                        Map<String, String> attributes = new HashMap<String, String>();
+                        String key = (String)e.getKey();
+                        String value = (String)e.getValue();
+                        // Unfortunately, the xalan file only has the classname
+                        if ("".equals(value)) {
+                            value = key;
+                            key = "";
+                        }
+                        if (!"".equals(key)) {
+                            attributes.put(key, value);
+                            attributes.put("uri", key);
+                        }
+                        attributes.put("class", value);
+                        ServiceDeclarationImpl descriptor = new ServiceDeclarationImpl(url, value, attributes);
+                        descriptors.add(descriptor);
+                    }
+                    continue;
+                }
+                BufferedReader reader = null;
+                try {
+                    reader = new BufferedReader(new InputStreamReader(is));
+                    int count = 0;
+                    while (true) {
+                        String line = reader.readLine();
+                        if (line == null)
+                            break;
+                        line = line.trim();
+                        if (!line.startsWith("#") && !"".equals(line)) {
+                            String reg = line.trim();
+                            if (debug) {
+                                logger.fine("Registering service provider: " + reg);
+                            }
+
+                            Map<String, String> attributes = parseServiceDeclaration(reg);
+                            String className = attributes.get("class");
+                            if (className == null) {
+                                // Add a unique class name to prevent equals() from returning true
+                                className = "_class_" + count;
+                                count++;
+                            }
+                            ServiceDeclarationImpl descriptor = new ServiceDeclarationImpl(url, className, attributes);
+                            descriptors.add(descriptor);
+                        }
+                    }
+                } finally {
+                    if (reader != null) {
+                        try {
+                            reader.close();
+                        } catch (IOException e) {
+                            // Ignore
+                        }
+                    }
+                }
+            }
+        } catch (IOException e) {
+            logger.log(Level.SEVERE, e.getMessage(), e);
+        }
+        return descriptors;
+
+    }
+
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDeclaration.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDeclaration.java
new file mode 100644
index 0000000000..d7ac8b449f
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDeclaration.java
@@ -0,0 +1,70 @@
+/*
+ * 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.extensibility;
+
+import java.net.URL;
+import java.util.Map;
+
+/**
+ * Service declaration using J2SE Jar service provider spec Classes specified
+ * inside this declaration are loaded using the ClassLoader used to read the
+ * configuration file corresponding to this declaration.
+ *
+ * @version $Rev$ $Date$
+ */
+public interface ServiceDeclaration {
+    /**
+     * Load a java class in the same context as the service definition
+     * @param className The class name
+     * @return The loaded class
+     * @throws ClassNotFoundException
+     */
+    Class<?> loadClass(String className) throws ClassNotFoundException;
+    
+    /**
+     * Get the java class for the service impl
+     * @return The java class
+     */
+    Class<?> loadClass() throws ClassNotFoundException;
+    
+    /**
+     * Get all attributes (name=value pairs) defined for the given entry
+     * @return All attributes keyed by name
+     */
+    Map<String, String> getAttributes();
+    
+    URL getLocation();
+    
+    String getClassName();
+    
+    URL getResource(String name);
+    
+    /**
+     * The service descriptor might be hashed
+     * @param obj Another object
+     * @return
+     */
+    boolean equals(Object obj);
+    /**
+     * The service descriptor might be hashed
+     * @return
+     */
+    int hashCode();
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscoverer.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscoverer.java
new file mode 100644
index 0000000000..6adf083411
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscoverer.java
@@ -0,0 +1,49 @@
+/*
+ * 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.extensibility;
+
+import java.io.IOException;
+import java.util.Set;
+
+/**
+ * A SPI that allows different implementations of discovering service declarations
+ */
+public interface ServiceDiscoverer {
+    
+    /**
+     * Get all service declarations for this interface
+     * 
+     * @param name
+     * @return set of service declarations
+     * @throws IOException
+     */
+    public Set<ServiceDeclaration> getServiceDeclarations(String name) throws IOException;
+    
+    /**
+     * Get first service declaration class for the given interface
+     * 
+     * @param name
+     * @return service implementation class
+     * @throws IOException
+     * @throws ClassNotFoundException
+     */
+    public ServiceDeclaration getFirstServiceDeclaration(String name) throws IOException;
+    
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java
new file mode 100644
index 0000000000..7976ea2f7b
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java
@@ -0,0 +1,87 @@
+/*
+ * 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.extensibility;
+
+import java.io.IOException;
+import java.util.Set;
+import java.util.logging.Logger;
+
+/**
+ * Service discovery for Tuscany based on J2SE Jar service provider spec.
+ * Services are described using configuration files in META-INF/services.
+ * Service description specifies a class name followed by optional properties.
+ * 
+ *
+ * @version $Rev$ $Date$
+ */
+public final class ServiceDiscovery implements ServiceDiscoverer {
+    private static final Logger logger = Logger.getLogger(ServiceDiscovery.class.getName());
+
+    private final static ServiceDiscovery INSTANCE = new ServiceDiscovery();
+
+    private ServiceDiscoverer discoverer;
+    
+    private ServiceDiscovery() {
+        super();
+    }
+    /**
+     * Get an instance of Service discovery, one instance is created per
+     * ClassLoader that this class is loaded from
+     * 
+     * @return
+     */
+    public static ServiceDiscovery getInstance() {
+        return INSTANCE;
+    }
+
+    public ServiceDiscoverer getServiceDiscoverer() {
+        if (discoverer != null) {
+            return discoverer;
+        }
+        try {
+            //FIXME Remove that upside-down dependency
+            Class.forName("org.apache.tuscany.sca.extensibility.equinox.EquinoxServiceDiscoverer");
+            if (discoverer != null) {
+                return discoverer;
+            }
+        } catch (Throwable e) {
+        }
+        discoverer = new ContextClassLoaderServiceDiscoverer();
+        return discoverer;
+    }
+
+    public void setServiceDiscoverer(ServiceDiscoverer sd) {
+        if (discoverer != null) {
+            throw new IllegalStateException("The ServiceDiscoverer cannot be reset");
+        }
+        discoverer = sd;
+    }
+
+    public Set<ServiceDeclaration> getServiceDeclarations(String name) throws IOException {
+        Set<ServiceDeclaration> services = getServiceDiscoverer().getServiceDeclarations(name);
+        return services;
+    }
+
+    public ServiceDeclaration getFirstServiceDeclaration(final String name) throws IOException {
+        ServiceDeclaration service = getServiceDiscoverer().getFirstServiceDeclaration(name);
+        return service;
+    }
+    
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/resources/META-INF/services/org.apache.tuscany.sca.core.FactoryExtensionPoint b/branches/sca-java-2.0-M2/modules/extensibility/src/main/resources/META-INF/services/org.apache.tuscany.sca.core.FactoryExtensionPoint
new file mode 100644
index 0000000000..3c135aa267
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/resources/META-INF/services/org.apache.tuscany.sca.core.FactoryExtensionPoint
@@ -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.core.DefaultFactoryExtensionPoint

diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/resources/META-INF/services/org.apache.tuscany.sca.core.ModuleActivatorExtensionPoint b/branches/sca-java-2.0-M2/modules/extensibility/src/main/resources/META-INF/services/org.apache.tuscany.sca.core.ModuleActivatorExtensionPoint
new file mode 100644
index 0000000000..42bad63132
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/resources/META-INF/services/org.apache.tuscany.sca.core.ModuleActivatorExtensionPoint
@@ -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.core.DefaultModuleActivatorExtensionPoint

diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/main/resources/META-INF/services/org.apache.tuscany.sca.core.UtilityExtensionPoint b/branches/sca-java-2.0-M2/modules/extensibility/src/main/resources/META-INF/services/org.apache.tuscany.sca.core.UtilityExtensionPoint
new file mode 100644
index 0000000000..d769bad283
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/main/resources/META-INF/services/org.apache.tuscany.sca.core.UtilityExtensionPoint
@@ -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.core.DefaultUtilityExtensionPoint

diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/test/java/org/apache/tuscany/sca/extensibility/ContextClassLoaderServiceDiscovererTestCase.java b/branches/sca-java-2.0-M2/modules/extensibility/src/test/java/org/apache/tuscany/sca/extensibility/ContextClassLoaderServiceDiscovererTestCase.java
new file mode 100644
index 0000000000..cfab64bef7
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/test/java/org/apache/tuscany/sca/extensibility/ContextClassLoaderServiceDiscovererTestCase.java
@@ -0,0 +1,81 @@
+/*
+ * 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.extensibility;
+
+import java.io.IOException;
+import java.util.Set;
+
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+/**
+ * Test Case for ClasspathServiceDiscover
+ */
+public class ContextClassLoaderServiceDiscovererTestCase {
+    private static ContextClassLoaderServiceDiscoverer discover;
+
+    /**
+     * @throws java.lang.Exception
+     */
+    @BeforeClass
+    public static void setUpBeforeClass() throws Exception {
+        discover = new ContextClassLoaderServiceDiscoverer();
+    }
+
+    @Test
+    public void testDiscovery() {
+        Set<ServiceDeclaration> discriptors =
+            discover.getServiceDeclarations("org.apache.tuscany.sca.core.ModuleActivatorExtensionPoint");
+        Assert.assertEquals(1, discriptors.size());
+        discriptors =
+            discover.getServiceDeclarations("notthere");
+        Assert.assertEquals(0, discriptors.size());
+    }
+    
+    @Test
+    public void testDiscoveryFirst() throws IOException {
+        ServiceDeclaration descriptor =
+            discover.getFirstServiceDeclaration("org.apache.tuscany.sca.core.ModuleActivatorExtensionPoint");
+        Assert.assertNotNull(descriptor);
+        descriptor = discover.getFirstServiceDeclaration("notthere");
+        Assert.assertNull(descriptor);
+    }
+    
+    @Test
+    public void testXPathFactory() {
+        Set<ServiceDeclaration> discriptors = discover.getServiceDeclarations("javax.xml.xpath.XPathFactory");
+        if (!discriptors.isEmpty()) {
+            ServiceDeclaration d = discriptors.iterator().next();
+            Assert.assertNotNull(d.getClassName());
+            Assert.assertTrue(d.getAttributes().containsKey("class"));
+        }
+    }
+
+
+    /**
+     * @throws java.lang.Exception
+     */
+    @AfterClass
+    public static void tearDownAfterClass() throws Exception {
+    }
+
+}
diff --git a/branches/sca-java-2.0-M2/modules/extensibility/src/test/java/org/apache/tuscany/sca/extensibility/DefaultExtensionPointRegistryTestCase.java b/branches/sca-java-2.0-M2/modules/extensibility/src/test/java/org/apache/tuscany/sca/extensibility/DefaultExtensionPointRegistryTestCase.java
new file mode 100644
index 0000000000..9758cba3b4
--- /dev/null
+++ b/branches/sca-java-2.0-M2/modules/extensibility/src/test/java/org/apache/tuscany/sca/extensibility/DefaultExtensionPointRegistryTestCase.java
@@ -0,0 +1,58 @@
+/*
+ * 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.extensibility;
+
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertSame;
+
+import org.apache.tuscany.sca.core.DefaultExtensionPointRegistry;
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.junit.Before;
+import org.junit.Test;
+
+public class DefaultExtensionPointRegistryTestCase {
+    private ExtensionPointRegistry registry;
+
+    @Before
+    public void setUp() throws Exception {
+        registry = new DefaultExtensionPointRegistry();
+    }
+
+    @Test
+    public void testRegistry() {
+        MyExtensionPoint service = new MyExtensionPointImpl();
+        registry.addExtensionPoint(service);
+        assertSame(service, registry.getExtensionPoint(MyExtensionPoint.class));
+        registry.removeExtensionPoint(service);
+        assertNull(registry.getExtensionPoint(MyExtensionPoint.class));
+    }
+
+    public static interface MyExtensionPoint {
+        void doSomething();
+    }
+
+    private static class MyExtensionPointImpl implements MyExtensionPoint {
+
+        public void doSomething() {
+        }
+
+    }
+
+}