如题，这个上传下载功能用的是jspsmartupload组件，要到网上下载jar包

先上一个简单的案例程序：

上传：

前台：

<%@ page contentType="text/html;charset=UTF-8"%>





	

	

	
  
		
   jspSmartUpload组件文件上传 
   

		
   
 
    
    
 
      
     

      
 
       
 
        

         上传文件1:
        
 
 
       

        
 
          
        
 
      
 
      
 
       
 
        

         上传文件2:
        
 
 
       

        
 
          
        
 
      
 
      
 
       
 
        
 
          
          
        
 
 
      
 
     
    
 
   
	
  

后台：

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.jspsmart.upload.SmartUpload;
public class SmartUploadServlet extends HttpServlet {
 private ServletConfig config;
 //初始化Servlet
 final public void init(ServletConfig config)
   throws ServletException{
  this.config=config;
 }
 //处理GET请求
 public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {

  this.doPost(request, response);
 }
 //响应POST请求
 public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
  //获取PrintWriter对象
  PrintWriter out = response.getWriter();
  out.println("");
  out.println("");
  out.println("");
  out.println("
  
   
");
  out.println("
   

   
jspSmartUpload
");
  out.println("
   

   
");
  //新建一个SmartUpload对象
  SmartUpload mySmartUpload=new SmartUpload();
  try{
   //上传初始化
   mySmartUpload.initialize(config, request, response);
   //设定每个上传文件的最大长度
   mySmartUpload.setMaxFileSize(1*512*1024);
   //设定总上传数据的长度
   mySmartUpload.setTotalMaxFileSize(1*1024*1024);
   //设定允许上传的文件的类型,只允许上传java,doc,txt文件
   mySmartUpload.setAllowedFilesList("java,doc,txt");
   //设定禁止上传的文件的类型,禁止上传带有exe,bat文件
   mySmartUpload.setDeniedFilesList("exe,bat");
   //上传文件
   mySmartUpload.upload();
   //将上传文件全部保存到指定目录
   String name = new String(mySmartUpload.getRequest().getParameter("paramete"));
   System.out.println(name);
   int count=mySmartUpload.save("/");
   out.println(//利用Request对象获取参数之值
     //String name= new String(request.getParameter("name").getBytes("ISO-8859-1"),"utf-8") ; 
     mySmartUpload.getRequest().getParameter("paramete")+" ");
   out.println(name);
   //显示处理结果
   out.println("
   "+count+" File Upload!
   
");
   //处理每个上传文件
   for(int i=0;i
   
    " +file.getFileName()+"
    
"); //打印文件扩展名 out.println("File ExtName: 
    " +file.getFileExt()+"
    
"); //打印文件路径,包括目录 out.println("Path: 
    " +file.getFilePathName()+"
    
"); //另存到以Web应用程序的根目录为文件根目录的目录下 //(声明一下：在Myeclipse中，该目录位于工程下的.metadata/.me_tcat/webapps/该工程目录/upload/) file.saveAs("/upload/"+file.getFileName(),mySmartUpload.SAVE_VIRTUAL); } } }catch(Exception e){//异常处理 //打印自定义异常信息 out.println("Unanable to upload the file.
    
"); out.println("Please Check The File Type"); } } } 
   
  

下载：

前台：

<%@ page contentType="text/html;charset=UTF-8"%>





	

	

	
  
		
   jspSmartUpload组件下载文件 
   

		
   
 
    
 
     

      
 
       
 
        
 
         文件1 
        
 
       
 
        
 
         文件2 
        
 
      
 
     
    
 
   
	
  

后台：