1 files changed, 114 insertions, 0 deletions
diff --git a/tags/java/sca/2.0-M3-RC3/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/resolver/DefaultModelResolverExtensionPoint.java b/tags/java/sca/2.0-M3-RC3/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/resolver/DefaultModelResolverExtensionPoint.java
new file mode 100644
index 0000000000..7cbf8d5528
--- /dev/null
+++ b/tags/java/sca/2.0-M3-RC3/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/resolver/DefaultModelResolverExtensionPoint.java
@@ -0,0 +1,114 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.    
+ */
+package org.apache.tuscany.sca.contribution.resolver;
+
+import java.io.IOException;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+import org.apache.tuscany.sca.extensibility.ServiceDiscovery;
+
+
+/**
+ * The default implementation of a model resolver extension point.
+ * 
+ * @version $Rev$ $Date$
+ */
+public class DefaultModelResolverExtensionPoint implements ModelResolverExtensionPoint {
+    
+    private final Map<Class<?>, Class<? extends ModelResolver>> resolvers = new HashMap<Class<?>, Class<? extends ModelResolver>>();
+    private Map<String, ServiceDeclaration> loadedResolvers;
+
+    /**
+     * Constructs a new DefaultModelResolverExtensionPoint.
+     */
+    public DefaultModelResolverExtensionPoint() {
+    }
+
+    public void addResolver(Class<?> modelType, Class<? extends ModelResolver> resolver) {
+        resolvers.put(modelType, resolver);
+    }
+
+    public void removeResolver(Class<?> modelType) {
+        resolvers.remove(modelType);
+    }
+
+    @SuppressWarnings("unchecked")
+    public Class<? extends ModelResolver> getResolver(Class<?> modelType) {
+        loadModelResolvers();
+        
+        Class<?>[] classes = modelType.getInterfaces();
+        for (Class<?> c : classes) {
+            Class<? extends ModelResolver> resolver = resolvers.get(c);
+            if (resolver == null) {
+                ServiceDeclaration resolverClass = loadedResolvers.get(c.getName());
+                if (resolverClass != null) {
+                    try {
+                        return (Class<? extends ModelResolver>)resolverClass.loadClass();
+                    } catch (ClassNotFoundException e) {
+                        throw new IllegalArgumentException(e);
+                    }
+                }
+            } else {
+                return resolver;
+            }
+        }
+
+        Class<? extends ModelResolver > resolver = resolvers.get(modelType);
+        if (resolver == null) {
+            ServiceDeclaration resolverClass = loadedResolvers.get(modelType.getName());
+            if (resolverClass != null) {
+                try {
+                    return (Class<? extends ModelResolver>)resolverClass.loadClass();
+                } catch (ClassNotFoundException e) {
+                    throw new IllegalArgumentException(e);
+                }
+            }
+        }
+        return resolver;
+    }
+
+    /**
+     * Dynamically load model resolvers declared under META-INF/services
+     */
+    private synchronized void loadModelResolvers() {
+        if (loadedResolvers != null)
+            return;
+        loadedResolvers = new HashMap<String, ServiceDeclaration>();
+
+        // Get the model resolver service declarations
+        Collection<ServiceDeclaration> modelResolverDeclarations; 
+        try {
+            modelResolverDeclarations = ServiceDiscovery.getInstance().getServiceDeclarations(ModelResolver.class.getName());
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        
+        // Load model resolvers
+        for (ServiceDeclaration modelResolverDeclaration: modelResolverDeclarations) {
+            Map<String, String> attributes = modelResolverDeclaration.getAttributes();
+            String model = attributes.get("model");
+
+            loadedResolvers.put(model, modelResolverDeclaration);
+        }
+    }
+
+}