1 files changed, 144 insertions, 0 deletions
diff --git a/tags/java/sca/1.5.1-RC1/modules/contribution-java/src/main/java/org/apache/tuscany/sca/contribution/java/DefaultContributionClassloaderProviderExtensionPoint.java b/tags/java/sca/1.5.1-RC1/modules/contribution-java/src/main/java/org/apache/tuscany/sca/contribution/java/DefaultContributionClassloaderProviderExtensionPoint.java
new file mode 100644
index 0000000000..7ffecdf312
--- /dev/null
+++ b/tags/java/sca/1.5.1-RC1/modules/contribution-java/src/main/java/org/apache/tuscany/sca/contribution/java/DefaultContributionClassloaderProviderExtensionPoint.java
@@ -0,0 +1,144 @@
+/*
+ * 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.java;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.reflect.Constructor;
+import java.net.MalformedURLException;
+import java.net.URI;
+import java.net.URL;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+import org.apache.tuscany.sca.contribution.Contribution;
+import org.apache.tuscany.sca.contribution.ModelFactoryExtensionPoint;
+import org.apache.tuscany.sca.contribution.processor.PackageProcessor;
+import org.apache.tuscany.sca.contribution.service.ContributionException;
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+import org.apache.tuscany.sca.extensibility.ServiceDiscovery;
+
+
+/**
+ * Default implementation of a contribution classloader provider extension point.
+ *
+ * @version $Rev$ $Date$
+ */
+public class DefaultContributionClassloaderProviderExtensionPoint implements ContributionClassloaderProviderExtensionPoint {
+    
+    private HashMap<String, ContributionClassLoaderProvider> providers = new HashMap<String, ContributionClassLoaderProvider>();
+    private boolean loaded;
+    
+    /**
+     * Constructs a new DefaultModelFactoryExtensionPoint.
+     */
+    public DefaultContributionClassloaderProviderExtensionPoint() {
+    }
+
+    /**
+     * Add a contribution classloader provider extension.
+     * 
+     * @param provider The provider to add
+     */
+    public void addProvider(ContributionClassLoaderProvider provider){
+        providers.put(provider.getContributionType(), provider);
+    }
+    
+    /**
+     * Remove a contribution classloader provider extension.
+     *  
+     * @param provider The provider to remove
+     */
+    public void removeProvider(ContributionClassLoaderProvider provider){
+        providers.remove(provider.getContributionType());
+    }
+    
+    /**
+     * Get a contribution classloader provider for the given contribution type.
+     * @param contributionType the lookup key 
+     * @return The provider
+     */
+    public ContributionClassLoaderProvider getProvider(String contributionType){
+        loadProviders();
+        return providers.get(contributionType);
+    }
+
+    private synchronized void loadProviders() {
+        if (loaded)
+            return;
+
+        // Get the processor service declarations
+        Set<ServiceDeclaration> processorDeclarations; 
+        try {
+            processorDeclarations = ServiceDiscovery.getInstance().getServiceDeclarations(ContributionClassLoaderProvider.class);
+        } catch (IOException e) {
+            throw new IllegalStateException(e);
+        }
+        
+        for (ServiceDeclaration processorDeclaration: processorDeclarations) {
+            Map<String, String> attributes = processorDeclaration.getAttributes();
+            
+            // Load a URL artifact processor
+            String contributionType = attributes.get("type");
+            
+            // Create a processor wrapper and register it
+            ContributionClassLoaderProvider provider = new LazyContributionClassLoaderProvider(contributionType, processorDeclaration);
+            addProvider(provider);
+        }
+        
+        loaded = true;
+    }
+
+    /**
+     * A facade for package processors.
+     */
+    private static class LazyContributionClassLoaderProvider implements ContributionClassLoaderProvider {
+        
+        private ServiceDeclaration processorDeclaration;
+        private String contributionType;
+        private ContributionClassLoaderProvider provider;
+        
+        private LazyContributionClassLoaderProvider(String contributionType, ServiceDeclaration processorDeclaration) {
+            this.processorDeclaration = processorDeclaration;
+            this.contributionType = contributionType;
+        }
+
+        public String getContributionType() {
+            return contributionType;
+        }
+        
+        @SuppressWarnings("unchecked")
+        public ClassLoader getClassLoader(Contribution contribution, ClassLoader parent){
+            if (provider == null) {
+                try {
+                    Class<ContributionClassLoaderProvider> providerClass = (Class<ContributionClassLoaderProvider>)processorDeclaration.loadClass();
+                    Constructor<ContributionClassLoaderProvider> constructor = providerClass.getConstructor();
+                    provider = constructor.newInstance();
+                } catch (Exception e) {
+                    throw new IllegalStateException(e);
+                }
+            }
+            return provider.getClassLoader(contribution, parent);
+        }
+    }
+
+}