diff options
author | antelder <antelder@13f79535-47bb-0310-9956-ffa450edef68> | 2011-08-03 09:21:41 +0000 |
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committer | antelder <antelder@13f79535-47bb-0310-9956-ffa450edef68> | 2011-08-03 09:21:41 +0000 |
commit | 1fb6a28a73ca17dbb8c4b3059db590e2f9620943 (patch) | |
tree | 71d9c9a70ce373cecc4597c2880a5047e0353d07 /sca-java-1.x/tags/1.6-TUSCANY-3909/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java | |
parent | 7ad16a07b4288227c531c485939318768129fb54 (diff) |
Correct tag name
git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@1153404 13f79535-47bb-0310-9956-ffa450edef68
Diffstat (limited to 'sca-java-1.x/tags/1.6-TUSCANY-3909/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java')
-rw-r--r-- | sca-java-1.x/tags/1.6-TUSCANY-3909/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/sca-java-1.x/tags/1.6-TUSCANY-3909/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java b/sca-java-1.x/tags/1.6-TUSCANY-3909/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java new file mode 100644 index 0000000000..a95ab253ae --- /dev/null +++ b/sca-java-1.x/tags/1.6-TUSCANY-3909/extensibility/src/main/java/org/apache/tuscany/sca/extensibility/ServiceDiscovery.java @@ -0,0 +1,170 @@ +/* + * 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.io.IOException; +import java.lang.reflect.InvocationTargetException; +import java.lang.reflect.Method; +import java.security.AccessController; +import java.security.PrivilegedAction; +import java.util.HashSet; +import java.util.Set; +import java.util.logging.Level; +import java.util.logging.Logger; + +/** + * Service discovery for Tuscany based on J2SE Jar service provider spec. + * Services are described using configuration files in META-INF/services. + * Service description specifies a class name followed by optional properties. + * + * + * @version $Rev$ $Date$ + */ +public class ServiceDiscovery { + private static final Logger logger = Logger.getLogger(ServiceDiscovery.class.getName()); + + private final static ServiceDiscovery INSTANCE = new ServiceDiscovery(); + + private ServiceDiscoverer discoverer; + private Set<ClassLoader> registeredClassLoaders = new HashSet<ClassLoader>(); + + /** + * Get an instance of Service discovery, one instance is created per + * ClassLoader that this class is loaded from + * + * @return + */ + public static ServiceDiscovery getInstance() { + return INSTANCE; + } + + public ServiceDiscoverer getServiceDiscoverer() { + if (discoverer == null) { + discoverer = new ClassLoaderServiceDiscoverer(); + } + return discoverer; + } + + public void setServiceDiscoverer(ServiceDiscoverer sd) { + if (discoverer != null) { + throw new IllegalStateException("The ServiceDiscoverer cannot be reset"); + } + discoverer = sd; + } + + /** + * @deprecated + * Register a ClassLoader with this discovery mechanism. Tuscany extension + * ClassLoaders are registered here. + * + * @param classLoader + */ + @Deprecated + public synchronized void registerClassLoader(ClassLoader classLoader) { + registeredClassLoaders.add(classLoader); + } + + /** + * @deprecated + * Unregister a ClassLoader with this discovery mechanism. + * + * @param classLoader + */ + @Deprecated + public synchronized void unregisterClassLoader(ClassLoader classLoader) { + registeredClassLoaders.remove(classLoader); + } + + /** + * Get all service declarations for this name + * + * @param name + * @return set of service declarations + * @throws IOException + */ + public Set<ServiceDeclaration> getServiceDeclarations(String name) throws IOException { + Set<ServiceDeclaration> services = getServiceDiscoverer().discover(name, false); + return services; + } + + /** + * Get all service declarations for this interface + * + * @param serviceInterface + * @return set of service declarations + * @throws IOException + */ + public Set<ServiceDeclaration> getServiceDeclarations(Class<?> serviceInterface) throws IOException { + + return getServiceDeclarations(serviceInterface.getName()); + } + + /** + * Load one service implementation class for this interface + * + * @param serviceInterface + * @return service implementation class + * @throws IOException + * @throws ClassNotFoundException + */ + public Class<?> loadFirstServiceClass(final Class<?> serviceInterface) throws IOException, ClassNotFoundException { + // Try System property first + String className = AccessController.doPrivileged(new PrivilegedAction<String>() { + public String run() { + return System.getProperty(serviceInterface.getName()); + } + }); + if (className != null) { + try { + // Try the classloader for the service interface first + return Class.forName(className, false, serviceInterface.getClassLoader()); + } catch (ClassNotFoundException e) { + try { + // Try the thread context classloader + return Class.forName(className, false, Thread.currentThread().getContextClassLoader()); + } catch (ClassNotFoundException ex) { + logger.log(Level.WARNING, ex.getMessage(), ex); + } + } + } + Set<ServiceDeclaration> services = getServiceDiscoverer().discover(serviceInterface.getName(), true); + if (services.isEmpty()) { + return null; + } + return services.iterator().next().loadClass(); + } + + /** + * Create a new instance of a factory service class. + * + * @param serviceInterface + * @return service implementation class + * @throws SecurityException + * @throws NoSuchMethodException + * @throws InvocationTargetException + * @throws IllegalAccessException + */ + public Object newFactoryClassInstance(final Class<?> serviceInterface) throws SecurityException, NoSuchMethodException, InvocationTargetException, IllegalAccessException { + Method newInstanceMethod = serviceInterface.getMethod("newInstance"); + Object factory = newInstanceMethod.invoke(null); + return factory; + } + +} |