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Diffstat (limited to '')
-rw-r--r-- | sca-java-2.x/branches/2.0-Beta1/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultModuleActivatorExtensionPoint.java | 154 |
1 files changed, 154 insertions, 0 deletions
diff --git a/sca-java-2.x/branches/2.0-Beta1/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultModuleActivatorExtensionPoint.java b/sca-java-2.x/branches/2.0-Beta1/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultModuleActivatorExtensionPoint.java new file mode 100644 index 0000000000..99792d0215 --- /dev/null +++ b/sca-java-2.x/branches/2.0-Beta1/modules/extensibility/src/main/java/org/apache/tuscany/sca/core/DefaultModuleActivatorExtensionPoint.java @@ -0,0 +1,154 @@ +/* + * 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 static org.apache.tuscany.sca.extensibility.ServiceHelper.newInstance; + +import java.io.IOException; +import java.util.ArrayList; +import java.util.Collection; +import java.util.List; +import java.util.Map; +import java.util.logging.Level; +import java.util.logging.Logger; + +import org.apache.tuscany.sca.extensibility.ServiceDeclaration; + +/** + * Default implementation of an extension point to hold Tuscany module activators. + * + * @version $Rev$ $Date$ + */ +public class DefaultModuleActivatorExtensionPoint implements ModuleActivatorExtensionPoint { + private final static Logger logger = Logger.getLogger(DefaultModuleActivatorExtensionPoint.class.getName()); + private List<ModuleActivator> activators = new ArrayList<ModuleActivator>(); + private boolean loadedActivators; + private boolean started; + private ExtensionPointRegistry registry; + + /** + * Constructs a new extension point. + */ + public DefaultModuleActivatorExtensionPoint(ExtensionPointRegistry registry) { + this.registry = registry; + } + + public void addModuleActivator(ModuleActivator activator) { + activators.add(activator); + } + + public List<ModuleActivator> getModuleActivators() { + loadModuleActivators(); + return activators; + } + + public void removeModuleActivator(ModuleActivator activator) { + if (activators.remove(activator)) { + activator.stop(); + } + } + + /** + * Dynamically load module activators declared under META-INF/services + */ + private synchronized void loadModuleActivators() { + if (loadedActivators) + return; + + // Get the activator service declarations + Collection<ServiceDeclaration> activatorDeclarations; + try { + // Load the module activators by ranking + activatorDeclarations = registry.getServiceDiscovery().getServiceDeclarations(ModuleActivator.class.getName(), true); + } catch (IOException e) { + throw new IllegalStateException(e); + } + + // Load and instantiate module activators + for (ServiceDeclaration activatorDeclaration : activatorDeclarations) { + if (logger.isLoggable(Level.FINE)) { + logger.fine("Loading " + activatorDeclaration.getClassName()); + } + ModuleActivator activator = null; + try { + Class<ModuleActivator> activatorClass = (Class<ModuleActivator>)activatorDeclaration.loadClass(); + try { + activator = newInstance(activatorClass, ExtensionPointRegistry.class, registry); + } catch (NoSuchMethodException e) { + try { + activator = + newInstance(activatorClass, + new Class<?>[] {ExtensionPointRegistry.class, Map.class}, + registry, + activatorDeclaration.getAttributes()); + + } catch (NoSuchMethodException e1) { + activator = newInstance(activatorClass); + + } + } + } catch (Throwable e) { + String optional = activatorDeclaration.getAttributes().get("optional"); + if ("true".equalsIgnoreCase(optional)) { + // If the optional flag is true, just log the error + logger.log(Level.SEVERE, e.getMessage(), e); + continue; + } else { + throw new IllegalArgumentException(e); + } + } + addModuleActivator(activator); + } + + loadedActivators = true; + } + + public void start() { + if (started) { + return; + } + getModuleActivators(); + for (ModuleActivator activator : activators) { + try { + activator.start(); + } catch (Throwable e) { + // Ignore the failing module for now + logger.log(Level.SEVERE, e.getMessage(), e); + } + } + started = true; + } + + public void stop() { + if (!started) { + return; + } + for (int i = activators.size() - 1; i >= 0; i--) { + try { + activators.get(i).stop(); + } catch (Throwable e) { + // Ignore the failing module for now + logger.log(Level.SEVERE, e.getMessage(), e); + } + } + started = false; + } + +} |