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>
}