类加载处理
package com.atom.util;import java.io.IOException;import java.io.InputStream;import java.net.URL;/** * <p> * <a href="ClassLoaderUtils.java.html"><i>View Source</i></a> * </p> * * @author KHT * @version $Id: ClassLoaderUtils.java 9326 2008-10-07 03:44:39Z bai $ */public class ClassLoaderUtils { /** * Load a given resource. * <p/> * This method will try to load the resource using the following methods (in order): * <ul> * <li>From {@link Thread#getContextClassLoader() Thread.currentThread().getContextClassLoader()} * <li>From {@link Class#getClassLoader() ClassLoaderUtil.class.getClassLoader()} * <li>From the {@link Class#getClassLoader() callingClass.getClassLoader() } * </ul> * * @param resourceName The name of the resource to load * @param callingClass The Class object of the calling object */ @SuppressWarnings("unchecked")public static URL getResource(String resourceName, Class callingClass) { URL url = null; url = Thread.currentThread().getContextClassLoader().getResource(resourceName); if (url == null) { url = ClassLoaderUtils.class.getClassLoader().getResource(resourceName); } if (url == null) { url = callingClass.getClassLoader().getResource(resourceName); } return url; } /** * This is a convenience method to load a resource as a stream. * <p/> * The algorithm used to find the resource is given in getResource() * * @param resourceName The name of the resource to load * @param callingClass The Class object of the calling object */ @SuppressWarnings("unchecked")public static InputStream getResourceAsStream(String resourceName, Class callingClass) { URL url = getResource(resourceName, callingClass); try { return (url != null) ? url.openStream() : null; } catch (IOException e) { return null; } } /** * Load a class with a given name. * <p/> * It will try to load the class in the following order: * <ul> * <li>From {@link Thread#getContextClassLoader() Thread.currentThread().getContextClassLoader()} * <li>Using the basic {@link Class#forName(java.lang.String) } * <li>From {@link Class#getClassLoader() ClassLoaderUtil.class.getClassLoader()} * <li>From the {@link Class#getClassLoader() callingClass.getClassLoader() } * </ul> * * @param className The name of the class to load * @param callingClass The Class object of the calling object * @throws ClassNotFoundException If the class cannot be found anywhere. */ @SuppressWarnings("unchecked")public static Class loadClass(String className, Class callingClass) throws ClassNotFoundException { try { return Thread.currentThread().getContextClassLoader().loadClass(className); } catch (ClassNotFoundException e) { try { return Class.forName(className); } catch (ClassNotFoundException ex) { try { return ClassLoaderUtils.class.getClassLoader().loadClass(className); } catch (ClassNotFoundException exc) { return callingClass.getClassLoader().loadClass(className); } } } } /** * Prints the current classloader hierarchy - useful for debugging. */ public static void printClassLoader() { System.out.println("ClassLoaderUtils.printClassLoader"); printClassLoader(Thread.currentThread().getContextClassLoader()); } /** * Prints the classloader hierarchy from a given classloader - useful for debugging. */ public static void printClassLoader(ClassLoader cl) { System.out.println("ClassLoaderUtils.printClassLoader(cl = " + cl + ")"); if (cl != null) { printClassLoader(cl.getParent()); } }}?