From 132aa8a77685ec92bc90c03f987650d275a7b639 Mon Sep 17 00:00:00 2001 From: lresende Date: Mon, 30 Sep 2013 06:59:11 +0000 Subject: 2.0.1 RC1 release tag git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@1527464 13f79535-47bb-0310-9956-ffa450edef68 --- .../tuscany/sca/extensibility/ServiceHelper.java | 226 +++++++++++++++++++++ 1 file changed, 226 insertions(+) create mode 100644 sca-java-2.x/tags/2.0.1-RC1/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceHelper.java (limited to 'sca-java-2.x/tags/2.0.1-RC1/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceHelper.java') diff --git a/sca-java-2.x/tags/2.0.1-RC1/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceHelper.java b/sca-java-2.x/tags/2.0.1-RC1/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceHelper.java new file mode 100644 index 0000000000..7f38aa6d06 --- /dev/null +++ b/sca-java-2.x/tags/2.0.1-RC1/modules/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceHelper.java @@ -0,0 +1,226 @@ +/* + * 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.extensibility; + +import java.lang.reflect.Constructor; +import java.lang.reflect.InvocationHandler; +import java.lang.reflect.Method; +import java.lang.reflect.Proxy; +import java.util.Collection; +import java.util.Map; + +import org.apache.tuscany.sca.core.ExtensionPointRegistry; +import org.apache.tuscany.sca.core.LifeCycleListener; + +/** + * A helper for handling service lifecycle and instantiations + * @tuscany.spi.extension.asclient + */ +public class ServiceHelper { + private ServiceHelper() { + } + + /** + * Start the service instance + * @param instance + */ + public static boolean start(Object instance) { + if (instance instanceof LifeCycleListener) { + ((LifeCycleListener)instance).start(); + return true; + } + return false; + } + + /** + * Stop the service instance + * @param instance + */ + public static boolean stop(Object instance) { + if (instance instanceof LifeCycleListener) { + ((LifeCycleListener)instance).stop(); + return true; + } + return false; + } + + /** + * Stop a collection of service instances + * @param instances + */ + public static void stop(Collection instances) { + if (instances == null) { + return; + } + for (Object instance : instances) { + if (instance instanceof LifeCycleListener) { + ((LifeCycleListener)instance).stop(); + } + } + } + + /** + * Create a service instance with one parameter + * @param cls The service type + * @param parameterType The parameter type + * @param parameter The parameter value + * @return The newly created service instance + * @throws Exception + */ + public static T newInstance(Class cls, Class parameterType, Object parameter) throws Exception { + Constructor constructor = cls.getConstructor(parameterType); + return constructor.newInstance(parameter); + } + + /** + * Create a service instance with an array of parameters + * @param cls The service type + * @param parameterTypes An array of parameter types + * @param parameters An array of parameter values + * @return The newly created service instance + * @throws Exception + */ + public static T newInstance(Class cls, Class parameterTypes[], Object... parameters) throws Exception { + Constructor constructor = cls.getConstructor(parameterTypes); + return constructor.newInstance(parameters); + } + + /** + * Create a service instance with the default no-arg constructor + * @param cls The service type + * @return The newly created service instance + * @throws Exception + */ + public static T newInstance(Class cls) throws Exception { + Constructor constructor = cls.getConstructor(); + return constructor.newInstance(); + } + + private final static Class[] ARG_TYPES = new Class[] {ExtensionPointRegistry.class, Map.class}; + + /** + * Create a service instance from the service declaration + * @param + * @param registry The extension point registry + * @param sd The service declaration + * @return The newly created service instance + * @throws Exception + */ + public static T newInstance(ExtensionPointRegistry registry, ServiceDeclaration sd) throws Exception { + Class cls = (Class)sd.loadClass(); + T instance = null; + try { + // Try constructor(ExtensionPointRegistry.class) + instance = newInstance(cls, ExtensionPointRegistry.class, registry); + } catch (NoSuchMethodException e) { + try { + // Try Try constructor(ExtensionPointRegistry.class, Map.class) + instance = newInstance(cls, ARG_TYPES, registry, sd.getAttributes()); + } catch (NoSuchMethodException e1) { + // Try constructor() + instance = newInstance(cls); + } + } + return instance; + } + + public static T newLazyInstance(ExtensionPointRegistry registry, ServiceDeclaration sd, Class serviceType) { + return serviceType.cast(Proxy.newProxyInstance(serviceType.getClassLoader(), + new Class[] {serviceType, LifeCycleListener.class}, + new InvocationHandlerImpl(registry, serviceType, sd))); + } + + private static class InvocationHandlerImpl implements InvocationHandler { + private ExtensionPointRegistry registry; + private Class type; + private ServiceDeclaration sd; + private Object instance; + + private final static Method STOP_METHOD = getMethod(LifeCycleListener.class, "stop"); + private final static Method START_METHOD = getMethod(LifeCycleListener.class, "start"); + private final static Method EQUALS_METHOD = getMethod(Object.class, "equals"); + private final static Method HASHCODE_METHOD = getMethod(Object.class, "hashCode"); + private final static Method TOSTRING_METHOD = getMethod(Object.class, "toString"); + + private static Method getMethod(Class type, String name) { + Method[] methods = type.getMethods(); + for (Method method : methods) { + if (name.equals(method.getName())) { + return method; + } + } + return null; + } + + public InvocationHandlerImpl(ExtensionPointRegistry registry, Class type, ServiceDeclaration sd) { + super(); + this.registry = registry; + this.sd = sd; + this.type = type; + } + + private Object getAttribute(Method method) throws Exception { + if (method.getParameterTypes().length != 0) { + return null; + } + String name = method.getName(); + if (name.equals("getModelType") && method.getReturnType() == Class.class) { + return sd.loadClass(sd.getAttributes().get("model")); + } else if (name.equals("getArtifactType")) { + return ServiceDeclarationParser.getQName(sd.getAttributes().get("qname")); + } + return null; + } + + public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { + synchronized (this) { + // Check if the method is to get the qname/model attribute + Object value = getAttribute(method); + if (value != null) { + return value; + } + if (instance == null && method.getDeclaringClass() == type) { + // Only initialize the instance when a method on the service type is invoked + instance = newInstance(registry, sd); + start(instance); + } + if (method.equals(EQUALS_METHOD)) { + return proxy == args[0]; + } else if (method.equals(HASHCODE_METHOD)) { + return System.identityHashCode(proxy); + } else if (method.equals(TOSTRING_METHOD)) { + return "Proxy: " + sd.toString(); + } + if (instance == null) { + return null; + } + } + if (method.equals(STOP_METHOD)) { + stop(instance); + return null; + } else if (method.equals(START_METHOD)) { + // Skip the start() + return null; + } else { + return method.invoke(instance, args); + } + } + } +} -- cgit v1.2.3