server 上传多个文件，修改文件名为 原文件名+系统时间戳
完整代码如下：

package com.commpim.performance;/**  * @author beaver  * @version 创建时间：2011-12-13 下午06:58:52  * 上传多个文件 */import java.io.BufferedOutputStream;import java.io.BufferedReader;import java.io.File;import java.io.FileNotFoundException;import java.io.FileOutputStream;import java.io.FileReader;import java.io.IOException;import java.io.InputStream;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Iterator;import java.util.List;import java.util.regex.Matcher;import java.util.regex.Pattern;import javax.servlet.ServletException;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.apache.commons.fileupload.FileItem;import org.apache.commons.fileupload.FileUploadException;import org.apache.commons.fileupload.disk.DiskFileItemFactory;import org.apache.commons.fileupload.servlet.ServletFileUpload;import org.apache.commons.fileupload.util.Streams;/** * Servlet implementation class for Servlet: UploadFile2Servlet * */ public class UploadFile2Servlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet { //用于存放上传文件的目录    private String uploadPath="E:\\upFile\\";    private File tempPath=new File("E:\\upFile\\temp");        /**     * 初始化Servlet，确保需要使用的目录都被建立<br>     * @throws javax.servlet.ServletException     */        @Override    public void init() throws ServletException{        if(!new File(uploadPath).isDirectory())            new File(uploadPath).mkdir();        if(!tempPath.isDirectory())            tempPath.mkdir();    }    /**     * 销毁Servelt     */    public void destory(){        super.destroy();    }       /**    * @param request    * @param response    * @throws javax.servlet.ServletException    * @throws java.io.IOException    */        protected void processRequest(HttpServletRequest request, HttpServletResponse response)    throws ServletException, IOException {                //创建一个上传项目工厂，并设置其缓存数据大小和临时文件保存位置        DiskFileItemFactory factory=new DiskFileItemFactory();        factory.setSizeThreshold(4096);        factory.setRepository(tempPath);                //使用项目工厂创建一个ServletFileUpload对象，用于解析文件上传请求        //并设置可以上传的文件的最大字节数，超过会抛出异常        ServletFileUpload upload=new ServletFileUpload(factory);        upload.setSizeMax(100000000);        upload.setHeaderEncoding("utf-8");                List fileItems=null;        try{            //开始读取上传信息            fileItems=upload.parseRequest(request);            //依次处理每一个上传的文件            Iterator itor=fileItems.iterator();            //正则匹配，过滤路径取文件名            String regExp=".+\\\\(.+)$";            //过滤文件类型            String[] errorType={".exe",".com",".cgi",".asp"};            Pattern p=Pattern.compile(regExp);            while(itor.hasNext()){                FileItem item=(FileItem)itor.next();                                //忽略其他不是文件域的所有其他表单信息                if(!item.isFormField()){                    String name=item.getName();                    long size=item.getSize();                    if((name==null||name.equals(""))&&size==0)                        continue;                    Matcher m=p.matcher(name);                    boolean result=m.find();                    //如果是允许上传的文件类型就执行上传操作                    if(result){                        for(int temp=0;temp<errorType.length;temp++){                            if(m.group(1).endsWith(errorType[temp])){                                throw new IOException(name+":wrong type");                            }                        }                        try{                            //保存文件到指定的目录，如果是保存到数据库，改写这里                        String fileName = name.substring(item.getName().lastIndexOf("\\")+1, name.length());//获得上传文件的文件名                                                 String date=new SimpleDateFormat("yyyyMMddHHmmss").format(Calendar.getInstance().getTime());                        fileName = fileName+"_"+date;                        String fn = uploadPath+fileName;                            File newf = new File(fn);                    if(!newf.exists()) {                    newf.createNewFile();                    }                    InputStream in = item.getInputStream();                    FileOutputStream fo = new FileOutputStream(newf);                    BufferedOutputStream out = new BufferedOutputStream(fo);//获得文件输出流                      Streams.copy(in, out, true);//开始把文件写到你指定的上传文件夹                             // item.write(new File(uploadPath,m.group(1)));                                                                                                }catch(Exception e){                        }                    }else{                        throw new IOException("fail to upload");                    }                }            }                    }catch(IOException e){        e.printStackTrace();        }catch(FileUploadException e1){            e1.printStackTrace();        }            }     // <editor-fold defaultstate="collapsed" desc="HttpServlet methods. Click on the + sign on the left to edit the code.">    /**     * Handles the HTTP <code>GET</code> method.    * @param request servlet request    * @param response servlet response    */    protected void doGet(HttpServletRequest request, HttpServletResponse response)    throws ServletException, IOException {        processRequest(request, response);    }    /**     * Handles the HTTP <code>POST</code> method.    * @param request servlet request    * @param response servlet response    */    protected void doPost(HttpServletRequest request, HttpServletResponse response)    throws ServletException, IOException {        processRequest(request, response);            }    /**     * Returns a short description of the servlet.    */    public String getServletInfo() {        return "cliff";    }    // </editor-fold>}