在web应用技术中经常使用文件的上传于下载，以下我效果以下我的代码了：

1.首先先导入 jsmartcom_zh_CN.jar 包

2.jsp页面的代码:

　　

 1 <%@ page language="java" import="java.util.*" pageEncoding="GB2312"%>
 2 <%
 3 String path = request.getContextPath();
 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
 5 %>
 6 
 7 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
 8 <html>
 9   <head>
10     <base href="<%=basePath%>">
11     
12     <title>My JSP 'index.jsp' starting page</title>
13     <meta http-equiv="pragma" content="no-cache">
14     <meta http-equiv="cache-control" content="no-cache">
15     <meta http-equiv="expires" content="0">    
16     <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
17     <meta http-equiv="description" content="This is my page">
18     <!--
19     <link rel="stylesheet" type="text/css" href="styles.css">
20     -->
21   </head>
22   
23   <body>
24       选择上传:
25        <form action="Upservlet" method="post" enctype="multipart/form-data">
26            选择1：<input type="file" name="up1"><br/>
27            选择2：<input type="file" name="up2">
28            <input type="submit" name="submit" value="提交">
29        </form>
30   </body>
31 </html>

3.Upservlet对应下的Java代码:

　　

 1 package com.zuxia.servlet;
 2 
 3 import java.io.IOException;
 4 import javax.servlet.ServletException;
 5 import javax.servlet.http.HttpServlet;
 6 import javax.servlet.http.HttpServletRequest;
 7 import javax.servlet.http.HttpServletResponse;
 8 import com.jspsmart.upload.File;
 9 import com.jspsmart.upload.Files;
10 import com.jspsmart.upload.SmartUpload;
11 public class Upservlet extends HttpServlet {
12 
13 
14     public void doGet(HttpServletRequest request, HttpServletResponse response)
15             throws ServletException, IOException {
16         
17         doPost(request, response);
18     }
19 
20 
21     public void doPost(HttpServletRequest request, HttpServletResponse response)
22             throws ServletException, IOException {
23         
24         //设置编码格式
25         request.setCharacterEncoding("GB2312");
26         response.setCharacterEncoding("GB2312");
27         
28         //第一步:新建一个对象
29         SmartUpload smart=new SmartUpload();
30         
31         //第二步:初始化
32         smart.initialize(super.getServletConfig(), request, response);
33         
34         //第三步:设置上传文件的类型
35         smart.setAllowedFilesList("jpg,html,pdf,txt,zip");
36         
37         try {
38             //第三步:上传文件
39             smart.upload();
40             
41             //第四步：保存文件
42             //smart.save("/imges");
43             //对文件进行重命名
44             Files fs= smart.getFiles();//得到所有的文件
45             
46             for (int i = 0; i <fs.getCount(); i++) {//对文件个数进行循环
47                 
48                 File f=fs.getFile(i);
49                 
50                 if (f.isMissing()==false) {//判断文件是否存在
51                     
52                     f.saveAs("/imges/"+System.currentTimeMillis()+f.getFileName());
53                 }
54                 
55             }
56             
57             
58         } catch (Exception e) {
59             
60             e.printStackTrace();
61         }
62         
63     }
64 
65 }