Java实现从jar包中读取指定文件的方法

package com.leo.util;import java.io.InputStream;import java.io.FileOutputStream;import java.util.jar.*;import java.util.Enumeration;public class JarFileAccess {  private static final String fileSeparator = System.getProperty("file.separator");  public void accessJarFile(String jarFileName, String fromDir, String toDir) throws Exception{    JarFile myJarFile = new JarFile(fromDir+fileSeparator+jarFileName);    Enumeration myEnum = myJarFile.entries();    while(myEnum.hasMoreElements()){      JarEntry myJarEntry = (JarEntry)myEnum.nextElement();      if(myJarEntry.getName().equals("jbossall-client.jar")){        InputStream is = myJarFile.getInputStream(myJarEntry);        FileOutputStream fos = new FileOutputStream(toDir+fileSeparator+myJarEntry.getName());        byte[] b = new byte[1024];        int len;        while((len = is.read(b))!= -1){          fos.write(b, 0, len);        }        fos.close();        is.close();        break;      } else{        continue;      }    }    myJarFile.close();  }}