Java tutorial
/* * Copyright 2003,2004 Colin Crist * * Licensed 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 hermes.impl; import hermes.browser.HermesBrowser; import hermes.config.ClasspathConfig; import hermes.config.PropertyConfig; import hermes.config.PropertySetConfig; import hermes.util.TextUtils; import java.io.File; import java.io.IOException; import java.lang.reflect.InvocationTargetException; import java.net.URL; import java.net.URLClassLoader; import java.net.URLStreamHandlerFactory; import java.util.ArrayList; import java.util.Enumeration; import java.util.HashSet; import java.util.Iterator; import java.util.List; import java.util.Set; import java.util.StringTokenizer; import java.util.jar.JarFile; import java.util.zip.ZipEntry; import javax.jms.ConnectionFactory; import javax.swing.ProgressMonitor; import org.apache.commons.beanutils.BeanUtils; import org.apache.log4j.Logger; /** * Helper for mucking about with ClassLoaders * * @author colincrist@hermesjms.com * @version $Id: LoaderSupport.java,v 1.29 2006/07/13 07:35:31 colincrist Exp $ */ public class LoaderSupport { private static final Logger log = Logger.getLogger(LoaderSupport.class); public static class DebugClassLoader extends URLClassLoader { /** * @param arg0 */ public DebugClassLoader(URL[] arg0) { super(arg0); } /** * @param arg0 * @param arg1 */ public DebugClassLoader(URL[] arg0, ClassLoader arg1) { super(arg0, arg1); } /** * @param arg0 * @param arg1 * @param arg2 */ public DebugClassLoader(URL[] arg0, ClassLoader arg1, URLStreamHandlerFactory arg2) { super(arg0, arg1, arg2); } /* * (non-Javadoc) * * @see java.lang.ClassLoader#loadClass(java.lang.String, boolean) */ protected synchronized Class loadClass(String arg0, boolean arg1) throws ClassNotFoundException { if (arg0.startsWith("hermes.ext")) { log.debug("loadClass(" + arg0 + ", " + arg1 + ") from " + toString()); } return super.loadClass(arg0, arg1); } public String toString() { StringBuffer rval = new StringBuffer(); rval.append("DebugClassLoader: "); for (int i = 0; i < getURLs().length; i++) { URL url = getURLs()[i]; rval.append(url.toString()); if (i != getURLs().length - 1) { rval.append(", "); } } if (getParent() instanceof DebugClassLoader) { rval.append(", parent=" + getParent().toString()); } return rval.toString(); } protected Class findClass(String name) throws ClassNotFoundException { return super.findClass(name); } } /** * Return ClassLoader given the list of ClasspathConfig instances. The * resulting loader can then be used to instantiate providers from those * libraries. */ static ClassLoader createClassLoader(List loaderConfigs, URL[] extraUrls, ClassLoader classLoader) throws IOException { int index = 0; int size = loaderConfigs.size(); if (extraUrls != null) { size += extraUrls.length; } URL[] urls = new URL[size]; StringBuffer debug = new StringBuffer("URLClassLoader: "); for (Iterator iter = loaderConfigs.iterator(); iter.hasNext();) { ClasspathConfig lConfig = (ClasspathConfig) iter.next(); URL url = null; if (lConfig.getJar().startsWith("http")) { url = new URL(TextUtils.replaceClasspathVariables(lConfig.getJar())); } else { url = new File(TextUtils.replaceClasspathVariables(lConfig.getJar())).toURL(); } urls[index++] = url; debug.append(url.toString()); if (iter.hasNext()) { debug.append(", "); } } if (extraUrls != null) { for (int i = 0; i < extraUrls.length; i++) { urls[index++] = extraUrls[i]; debug.append(", " + extraUrls[i].toString()); } } log.debug(debug.toString()); return new DebugClassLoader(urls, classLoader); } static ClassLoader createClassLoader(List loaderConfigs, ClassLoader classLoader) throws IOException { return createClassLoader(loaderConfigs, null, classLoader); } /** * Return ClassLoader given the list of ClasspathConfig instances. The * resulting loader can then be used to instantiate providers from those * libraries. */ static List lookForFactories(final List loaderConfigs, final ClassLoader baseLoader) throws IOException { final List rval = new ArrayList(); for (Iterator iter = loaderConfigs.iterator(); iter.hasNext();) { final ClasspathConfig lConfig = (ClasspathConfig) iter.next(); if (lConfig.getFactories() != null) { log.debug("using cached " + lConfig.getFactories()); for (StringTokenizer tokens = new StringTokenizer(lConfig.getFactories(), ","); tokens .hasMoreTokens();) { rval.add(tokens.nextToken()); } } else if (lConfig.isNoFactories()) { log.debug("previously scanned " + lConfig.getJar()); } else { Runnable r = new Runnable() { public void run() { final List localFactories = new ArrayList(); boolean foundFactory = false; StringBuffer factoriesAsString = null; try { log.debug("searching " + lConfig.getJar()); ClassLoader l = createClassLoader(loaderConfigs, baseLoader); JarFile jarFile = new JarFile(lConfig.getJar()); ProgressMonitor monitor = null; int entryNumber = 0; if (HermesBrowser.getBrowser() != null) { monitor = new ProgressMonitor(HermesBrowser.getBrowser(), "Looking for factories in " + lConfig.getJar(), "Scanning...", 0, jarFile.size()); monitor.setMillisToDecideToPopup(0); monitor.setMillisToPopup(0); monitor.setProgress(0); } for (Enumeration iter = jarFile.entries(); iter.hasMoreElements();) { ZipEntry entry = (ZipEntry) iter.nextElement(); entryNumber++; if (monitor != null) { monitor.setProgress(entryNumber); monitor.setNote("Checking entry " + entryNumber + " of " + jarFile.size()); } if (entry.getName().endsWith(".class")) { String s = entry.getName().substring(0, entry.getName().indexOf(".class")); s = s.replaceAll("/", "."); try { if (s.startsWith("hermes.browser") || s.startsWith("hermes.impl") || s.startsWith("javax.jms")) { // NOP } else { Class clazz = l.loadClass(s); if (!clazz.isInterface()) { if (implementsOrExtends(clazz, ConnectionFactory.class)) { foundFactory = true; localFactories.add(s); if (factoriesAsString == null) { factoriesAsString = new StringBuffer(); factoriesAsString.append(clazz.getName()); } else { factoriesAsString.append(",").append(clazz.getName()); } log.debug("found " + clazz.getName()); } } /** * TODO: remove Class clazz = l.loadClass(s); * Class[] interfaces = clazz.getInterfaces(); * for (int i = 0; i < interfaces.length; i++) { * if * (interfaces[i].equals(TopicConnectionFactory.class) || * interfaces[i].equals(QueueConnectionFactory.class) || * interfaces[i].equals(ConnectionFactory.class)) { * foundFactory = true; localFactories.add(s); * if (factoriesAsString == null) { * factoriesAsString = new * StringBuffer(clazz.getName()); } else { * factoriesAsString.append(",").append(clazz.getName()); } * log.debug("found " + clazz.getName()); } } */ } } catch (Throwable t) { // NOP } } } } catch (IOException e) { log.error("unable to access jar/zip " + lConfig.getJar() + ": " + e.getMessage(), e); } if (!foundFactory) { lConfig.setNoFactories(true); } else { lConfig.setFactories(factoriesAsString.toString()); rval.addAll(localFactories); } } }; r.run(); } } return rval; } /** * Indicates if a class or interface implements or extends the specified * interfaces or classes. If the specified <CODE>Class</CODE> is a class, * this method will recursively test if this class, its superclass or one of * the implemented interfaces of this class implements the specified * interface.<BR> * If the specified <CODE>Class</CODE> is an interface, this method will * recursively test if this interface or one of the implemented interfaces of * this interface implements the specified interface.<BR> * * @param clazz * the class or interface in question * @param testInterface * the class or interface to test against * @return <CODE>true</CODE> if the specified interfaces is implemented by * this class or one of its super-classes or interfaces */ public static boolean implementsOrExtends(Class clazz, Class testInterface) { Class[] implementedInterfaces = clazz.getInterfaces(); // test interface if (clazz.equals(testInterface)) { return true; // possibly the end of the recursion } for (int i = 0; i < implementedInterfaces.length; i++) { if (implementsOrExtends(implementedInterfaces[i], testInterface)) { return true; // recursion } } // maybe the superclass implements this interface ? Class superClass = clazz.getSuperclass(); if (superClass != null && implementsOrExtends(superClass, testInterface)) { return true; // recursion } return false; } public static void populateBean(Object bean, PropertySetConfig propertySet) throws IllegalAccessException, InvocationTargetException, NoSuchMethodException, IOException { if (propertySet != null) { Set appliedProperties = new HashSet(); for (Iterator iter = propertySet.getProperty().iterator(); iter.hasNext();) { PropertyConfig propertyConfig = (PropertyConfig) iter.next(); if (appliedProperties.contains(propertyConfig.getName())) { iter.remove(); } else { try { BeanUtils.setProperty(bean, propertyConfig.getName(), TextUtils.replaceClasspathVariables(propertyConfig.getValue())); appliedProperties.add(propertyConfig.getName()); log.debug("set " + bean.getClass().getName() + " " + propertyConfig.getName() + "=" + TextUtils.replaceClasspathVariables(propertyConfig.getValue())); } catch (InvocationTargetException t) { log.error( "unable to set property name=" + propertyConfig.getName() + " value=" + propertyConfig.getValue() + " on object of class " + bean.getClass().getName() + ": " + t.getCause().getMessage(), t.getCause()); } } } } } }