java 动态加载jar包（推荐一）

package org.util;import java.io.File;import java.io.IOException;import java.net.MalformedURLException;import java.net.URL;import java.net.URLClassLoader;import java.util.ArrayList;import java.util.Enumeration;import java.util.List;import java.util.jar.JarEntry;import java.util.jar.JarFile;import DC.Utility.Configuration;public class ClassLoad { static URLClassLoader loader = null; /**  * 在默认的目录加载jar  * @return  */ public static URLClassLoader getClassLoad() {  Configuration config = new Configuration(Configuration.getRoot()+File.separator    + "classpath.properties");  if (loader == null) {   URLClassLoaderUtil urlClass = new URLClassLoaderUtil(config     .getValue("classpath1"), false);   loader = urlClass.getClassLoader();  }  return loader; } /**  * 在给定的路径加载jar文件  * @param url  指定路径  * @param isFile  true 文件  false 目录  * @return  */ public static URLClassLoader getClassLoad(String url, boolean isFile) {  URLClassLoaderUtil urlClass = new URLClassLoaderUtil(url, false);  URLClassLoader loader = urlClass.getClassLoader();  return loader; }} class URLClassLoaderUtil { URLClassLoader classLoader = null;// URLClassLoader类载入器 private String jarFileName; private boolean isFile = true; List<String> jars = new ArrayList<String>(0); /**  * 加载具体的某一jar包  *   * @param jarFileName  */ public URLClassLoaderUtil(String jarFileName) {  this.setJarFileName(jarFileName);  this.inti(); } /**  * 加载jar包 当isFile为false是加载文件夹下所有jar  *   * @param jarFileName  *            路径  * @param isFile  */ public URLClassLoaderUtil(String jarFileName, boolean isFile) {  this.setJarFileName(jarFileName);  this.setFile(isFile);  this.inti(); } /**  *初始化，读取文件信息，并将jar文件路径加入到classpath  */ private void inti() {  // 添加jar文件路径到classpath  if (this.isFile) {   File f = new File(jarFileName);   addPath(f.toURI().toString());   jars.add(f.getAbsolutePath());  } else {   ReadJarFile df = new ReadJarFile(jarFileName, new String[] { "jar",     "zip" });   this.jars = df.getFiles();   List<String> jarURLs = df.getFilesURL();   Object[] o = jarURLs.toArray();   addPath(o);  } } /**  *回叫方法，class操作  *   *@paramcallBack  */ public void callBack() {  for (String s : this.jars) {   loadClass(s);  } } /**  *添加单个jar路径到classpath  *   *@paramjarURL  */ private void addPath(String jarURL) {  try {   classLoader = new URLClassLoader(new URL[] { new URL(jarURL) });  } catch (MalformedURLException e) {   e.printStackTrace();  } } /**  *添加jar路径到classpath  *   *@paramjarURLs  */ private void addPath(Object[] jarURLs) {  URL[] urls = new URL[jarURLs.length];  for (int i = 0; i < jarURLs.length; i++) {   try {    System.out.println(jarURLs[i].toString());    urls[i] = new URL(jarURLs[i].toString());   } catch (MalformedURLException e) {    e.printStackTrace();   }  }  classLoader = new URLClassLoader(urls); } /**  *动态载入class  *   *@paramjarFileName  *@paramcallBack  */// private void loadClass(String jarFileName, ClassCallBack callBack) {  private void loadClass(String jarFileName) {   JarFile jarFile = null;   try {    jarFile = new JarFile(jarFileName);   } catch (IOException e) {    e.printStackTrace();   }   Enumeration<JarEntry> en = jarFile.entries();   while (en.hasMoreElements()) {    JarEntry je = en.nextElement();    String name = je.getName();    String s5 = name.replace('/', '.');    if (s5.lastIndexOf(".class") > 0) {     String className = je.getName().substring(0,       je.getName().length() - ".class".length()).replace('/',       '.');     Class c = null;     try {      c = this.classLoader.loadClass(className);      System.out.println(className);     } catch (ClassNotFoundException e) {      System.out.println("NO CLASS: " + className);      // continue;     } catch (NoClassDefFoundError e) {      System.out.println("NO CLASS: " + className);      // continue;     }//     callBack.operate(c);    }   }  } public String getJarFileName() {  return jarFileName; } /**  * 设置jar路径  *   * @param jarFileName  */ public void setJarFileName(String jarFileName) {  this.jarFileName = jarFileName; } public boolean isFile() {  return isFile; } public URLClassLoader getClassLoader() {  return classLoader; } public void setClassLoader(URLClassLoader classLoader) {  this.classLoader = classLoader; } public void setFile(boolean isFile) {  this.isFile = isFile; }}/** * 读取jarwenjian * @author hml * */class ReadJarFile { List<String> jarList = new ArrayList<String>(); List<String> filesURL = new ArrayList<String>(); /**  * 读取指定文件夹的文件  *   * @param jarFileName  *            路径  * @param strings  *            后缀  */ public ReadJarFile(String jarFileName, String[] strings) {  // TODO Auto-generated constructor stub  File f = new File(jarFileName);  File[] fl = f.listFiles();  for (File file : fl) {   for (String str : strings) {    if (file.getName().endsWith(str)) {     jarList.add(file.getName());     filesURL.add(file.toURI().toString());    }   }  } } /**  * 获取文件名  *   * @return  */ public List<String> getFiles() {  // TODO Auto-generated method stub  return filesURL; } /**  * 获取文件路径  *   * @return  */ public List<String> getFilesURL() {  // TODO Auto-generated method stub  return filesURL; }}