1 files changed, 131 insertions, 0 deletions
diff --git a/sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/resolver/DefaultModelResolverExtensionPoint.java b/sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/resolver/DefaultModelResolverExtensionPoint.java
new file mode 100644
index 0000000000..a1eb85edca
--- /dev/null
+++ b/sca-java-2.x/tags/2.0.1-RC1/modules/contribution/src/main/java/org/apache/tuscany/sca/contribution/resolver/DefaultModelResolverExtensionPoint.java
@@ -0,0 +1,131 @@
+/*
+ * 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.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.StringTokenizer;
+
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+
+
+/**
+ * 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;
+    private ExtensionPointRegistry registry;
+
+    /**
+     * Constructs a new DefaultModelResolverExtensionPoint.
+     */
+    public DefaultModelResolverExtensionPoint(ExtensionPointRegistry registry) {
+        this.registry = registry;
+    }
+
+    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 = registry.getServiceDiscovery().getServiceDeclarations(ModelResolver.class, true);
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        
+        List<ServiceDeclaration> list = new ArrayList<ServiceDeclaration>(modelResolverDeclarations);
+        
+        // Load model resolvers, add entries from lower ranking to higher ranking so that higher ranking ones override
+        // the map
+        for (int i = list.size() - 1; i >= 0; i--) {
+            ServiceDeclaration modelResolverDeclaration = list.get(i);
+            Map<String, String> attributes = modelResolverDeclaration.getAttributes();
+            String model = attributes.get("model");
+            // The model can be a list of interfaces so that one model resolver can be used
+            // to resolve different types of models
+            if (model != null) {
+                StringTokenizer tokenizer = new StringTokenizer(model);
+                while (tokenizer.hasMoreTokens()) {
+                    String key = tokenizer.nextToken();
+                    loadedResolvers.put(key, modelResolverDeclaration);
+                }
+
+            }
+        }
+    }
+
+}