java动态加载jar包

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;
 }

}

原文地址:https://www.cnblogs.com/langlang/p/1890632.html