1 files changed, 152 insertions, 0 deletions
diff --git a/tags/java/sca/2.0-M3-RC5/modules/assembly/src/main/java/org/apache/tuscany/sca/assembly/builder/DefaultCompositeBuilderExtensionPoint.java b/tags/java/sca/2.0-M3-RC5/modules/assembly/src/main/java/org/apache/tuscany/sca/assembly/builder/DefaultCompositeBuilderExtensionPoint.java
new file mode 100644
index 0000000000..32444349b2
--- /dev/null
+++ b/tags/java/sca/2.0-M3-RC5/modules/assembly/src/main/java/org/apache/tuscany/sca/assembly/builder/DefaultCompositeBuilderExtensionPoint.java
@@ -0,0 +1,152 @@
+/*
+ * 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.builder;
+
+import java.lang.reflect.Constructor;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.apache.tuscany.sca.assembly.Composite;
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.apache.tuscany.sca.core.FactoryExtensionPoint;
+import org.apache.tuscany.sca.core.UtilityExtensionPoint;
+import org.apache.tuscany.sca.definitions.Definitions;
+import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
+import org.apache.tuscany.sca.extensibility.ServiceDiscovery;
+import org.apache.tuscany.sca.interfacedef.InterfaceContractMapper;
+import org.apache.tuscany.sca.monitor.Monitor;
+
+/**
+ * Default implementation of a provider factory extension point.
+ *
+ * @version $Rev$ $Date$
+ */
+public class DefaultCompositeBuilderExtensionPoint implements CompositeBuilderExtensionPoint {
+
+    private ExtensionPointRegistry registry;
+    private final Map<String, CompositeBuilder> builders = new HashMap<String, CompositeBuilder>();
+    private boolean loaded;
+
+    public DefaultCompositeBuilderExtensionPoint(ExtensionPointRegistry registry) {
+        this.registry = registry;
+    }
+
+    public void addCompositeBuilder(CompositeBuilder builder) {
+        builders.put(builder.getID(), builder);
+    }
+
+    public void removeCompositeBuilder(CompositeBuilder builder) {
+        builders.remove(builder.getID());
+    }
+
+    public CompositeBuilder getCompositeBuilder(String id) {
+        loadBuilders();
+        return builders.get(id);
+    }
+
+    /**
+     * Load builders declared under META-INF/services.
+     */
+    private synchronized void loadBuilders() {
+        if (loaded)
+            return;
+
+        FactoryExtensionPoint factories = registry.getExtensionPoint(FactoryExtensionPoint.class);
+
+        UtilityExtensionPoint utils = registry.getExtensionPoint(UtilityExtensionPoint.class);
+        InterfaceContractMapper mapper = utils.getUtility(InterfaceContractMapper.class);
+
+        // Get the provider factory service declarations
+        Collection<ServiceDeclaration> builderDeclarations;
+        ServiceDiscovery serviceDiscovery = ServiceDiscovery.getInstance();
+        try {
+            builderDeclarations = serviceDiscovery.getServiceDeclarations(CompositeBuilder.class.getName());
+        } catch (Exception e) {
+            throw new IllegalStateException(e);
+        }
+
+        for (ServiceDeclaration builderDeclaration : builderDeclarations) {
+        Map<String, String> attributes = builderDeclaration.getAttributes();
+            String id = attributes.get("id");
+
+            CompositeBuilder builder = new LazyCompositeBuilder(registry, id, builderDeclaration, this, factories, mapper);
+            builders.put(id, builder);
+        }
+    }
+
+    /**
+     * A wrapper around a composite builder allowing lazy
+     * loading and initialization of implementation providers.
+     */
+    private static class LazyCompositeBuilder implements CompositeBuilder {
+
+        private ExtensionPointRegistry registry;
+        private FactoryExtensionPoint factories;
+        private InterfaceContractMapper mapper;
+        private String id;
+        private ServiceDeclaration builderDeclaration;
+        private CompositeBuilder builder;
+        private CompositeBuilderExtensionPoint builders;
+
+        private LazyCompositeBuilder(ExtensionPointRegistry registry, String id, ServiceDeclaration factoryDeclaration,
+                                     CompositeBuilderExtensionPoint builders, FactoryExtensionPoint factories, InterfaceContractMapper mapper) {
+            this.registry = registry;
+            this.id = id;
+            this.builderDeclaration = factoryDeclaration;
+            this.builders = builders;
+            this.factories = factories;
+            this.mapper = mapper;
+        }
+
+        public String getID() {
+            return id;
+        }
+
+        public void build(Composite composite, Definitions definitions, Monitor monitor) throws CompositeBuilderException {
+            getBuilder().build(composite, definitions, monitor);
+        }
+
+        private CompositeBuilder getBuilder() {
+            if (builder == null) {
+                try {
+                    Class<CompositeBuilder> builderClass = (Class<CompositeBuilder>)builderDeclaration.loadClass();
+                    try {
+                        Constructor<CompositeBuilder> constructor = builderClass.getConstructor(FactoryExtensionPoint.class, InterfaceContractMapper.class);
+                        builder = constructor.newInstance(factories, mapper);
+                    } catch (NoSuchMethodException e) {
+                        try {
+                            Constructor<CompositeBuilder> constructor = builderClass.getConstructor(CompositeBuilderExtensionPoint.class, FactoryExtensionPoint.class, InterfaceContractMapper.class);
+                            builder = constructor.newInstance(builders, factories, mapper);
+                        } catch (NoSuchMethodException ex) {
+                            Constructor<CompositeBuilder> constructor = builderClass.getConstructor(ExtensionPointRegistry.class);
+                            builder = constructor.newInstance(registry);
+                        }
+                    }
+                } catch (Exception e) {
+                    throw new IllegalStateException(e);
+                }
+            }
+            return builder;
+        }
+
+    }
+
+}