| /* |
| * 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.ref.WeakReference; |
| import java.net.URL; |
| import java.security.AccessController; |
| import java.security.PrivilegedAction; |
| import java.security.PrivilegedActionException; |
| import java.security.PrivilegedExceptionAction; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Enumeration; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.logging.Level; |
| import java.util.logging.Logger; |
| |
| /** |
| * A ServiceDiscoverer that find META-INF/services/... using the Context ClassLoader. |
| * |
| * @version $Rev$ $Date$ |
| */ |
| public class ContextClassLoaderServiceDiscoverer implements ServiceDiscoverer { |
| private static final Logger logger = Logger.getLogger(ContextClassLoaderServiceDiscoverer.class.getName()); |
| |
| public class ServiceDeclarationImpl implements ServiceDeclaration { |
| private URL url; |
| private String className; |
| private Class<?> javaClass; |
| private Map<String, String> attributes; |
| |
| public ServiceDeclarationImpl(URL url, String className, Map<String, String> attributes) { |
| super(); |
| this.url = url; |
| this.className = className; |
| this.attributes = attributes; |
| } |
| |
| public Map<String, String> getAttributes() { |
| return attributes; |
| } |
| |
| public String getClassName() { |
| return className; |
| } |
| |
| public URL getLocation() { |
| return url; |
| } |
| |
| public Class<?> loadClass() throws ClassNotFoundException { |
| if (className == null) { |
| return null; |
| } |
| if (javaClass == null) { |
| javaClass = loadClass(className); |
| } |
| return javaClass; |
| } |
| |
| public Class<?> loadClass(String className) throws ClassNotFoundException { |
| return Class.forName(className, false, classLoaderReference.get()); |
| } |
| |
| @Override |
| public String toString() { |
| StringBuffer sb = new StringBuffer(); |
| sb.append("Location: ").append(url); |
| sb.append(" ClassLoader: ").append(classLoaderReference.get()); |
| sb.append(" Attributes: ").append(attributes); |
| return sb.toString(); |
| } |
| |
| public URL getResource(final String name) { |
| return AccessController.doPrivileged(new PrivilegedAction<URL>() { |
| public URL run() { |
| return classLoaderReference.get().getResource(name); |
| } |
| }); |
| } |
| |
| public boolean isAssignableTo(Class<?> serviceType) { |
| try { |
| loadClass(); |
| } catch (ClassNotFoundException e) { |
| // Ignore |
| } |
| return (javaClass != null && serviceType.isAssignableFrom(javaClass)); |
| } |
| |
| @Override |
| public Enumeration<URL> getResources(String name) throws IOException { |
| return Collections.enumeration(ContextClassLoaderServiceDiscoverer.this.getResources(name)); |
| } |
| } |
| |
| private WeakReference<ClassLoader> classLoaderReference; |
| |
| public ContextClassLoaderServiceDiscoverer() { |
| ClassLoader classLoader = Thread.currentThread().getContextClassLoader(); |
| this.classLoaderReference = new WeakReference<ClassLoader>(classLoader); |
| } |
| |
| public ContextClassLoaderServiceDiscoverer(ClassLoader classLoader) { |
| if (classLoader == null) { |
| classLoader = Thread.currentThread().getContextClassLoader(); |
| } |
| this.classLoaderReference = new WeakReference<ClassLoader>(classLoader); |
| } |
| |
| public ClassLoader getContextClassLoader() { |
| //return classLoaderReference.get(); |
| return Thread.currentThread().getContextClassLoader(); |
| } |
| |
| private Collection<URL> getResources(final String name) throws IOException { |
| try { |
| return AccessController.doPrivileged(new PrivilegedExceptionAction<Collection<URL>>() { |
| public Collection<URL> run() throws IOException { |
| List<URL> urls = Collections.list(classLoaderReference.get().getResources(name)); |
| // Eliminate the duplicate URLs (which can be found from child/parent classloaders) |
| return new HashSet<URL>(urls); |
| } |
| }); |
| } catch (PrivilegedActionException e) { |
| throw (IOException)e.getException(); |
| } |
| } |
| |
| public ServiceDeclaration getServiceDeclaration(String name) throws IOException { |
| Collection<ServiceDeclaration> declarations = getServiceDeclarations(name); |
| if (declarations.isEmpty()) { |
| return null; |
| } else { |
| return declarations.iterator().next(); |
| } |
| } |
| |
| public Collection<ServiceDeclaration> getServiceDeclarations(String serviceName) { |
| Collection<ServiceDeclaration> descriptors = new HashSet<ServiceDeclaration>(); |
| |
| // http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/xpath/XPathFactory.html |
| boolean isPropertyFile = "javax.xml.xpath.XPathFactory".equals(serviceName); |
| |
| String name = serviceName; |
| if (serviceName.startsWith("/")) { |
| // If the service name starts with /, treat it as the entry name |
| name = serviceName.substring(1); |
| } else { |
| // Use JDK SPI pattern |
| name = "META-INF/services/" + serviceName; |
| } |
| |
| boolean debug = logger.isLoggable(Level.FINE); |
| try { |
| for (final URL url : getResources(name)) { |
| if (debug) { |
| logger.fine("Reading service provider file: " + url.toExternalForm()); |
| } |
| |
| for (Map<String, String> attributes : ServiceDeclarationParser.load(url, isPropertyFile)) { |
| String className = attributes.get("class"); |
| ServiceDeclarationImpl descriptor = new ServiceDeclarationImpl(url, className, attributes); |
| descriptors.add(descriptor); |
| } |
| } |
| } catch (IOException e) { |
| logger.log(Level.SEVERE, e.getMessage(), e); |
| } |
| return descriptors; |
| |
| } |
| |
| } |