Servlet response下载文件

心已赠人 2022-04-13 03:21 320阅读 0赞

package com.wlt.response.c.body;

import java.io.IOException;  
import java.io.InputStream;

import javax.servlet.ServletContext;  
import javax.servlet.ServletException;  
import javax.servlet.ServletOutputStream;  
import javax.servlet.annotation.WebServlet;  
import javax.servlet.http.HttpServlet;  
import javax.servlet.http.HttpServletRequest;  
import javax.servlet.http.HttpServletResponse;

import org.apache.tomcat.util.http.fileupload.IOUtils;

/\*\*  
 \* 文件下载  
 \*/  
@WebServlet("/download")  
public class DownloadServlet extends HttpServlet \{  
    private static final long serialVersionUID = 1L;

/\*\*  
     \* @see HttpServlet\#doGet(HttpServletRequest request, HttpServletResponse response)  
     \*/  
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
        //   
        String filename = request.getParameter(" ");  
        ServletContext s = this.getServletContext();  
        //设置mine  
        String mt = s.getMimeType(filename);  
        response.setContentType(mt);  
          
        //设置下载头信息  
        response.setHeader("content-disposition", "attchment;filename="+filename);  
        //对考流  
        //获取输入流  
        InputStream is = s.getResourceAsStream("/download/"+filename);  
        //获取输出流  
        ServletOutputStream os = response.getOutputStream();  
          
        /\*  第一种

int len=-1;  
        byte\[\] b=new byte\[1024\];  
        while ((len=is.read(b))!=-1) \{  
            os.write(b,0,len);  
        \}\*/

// 第二种：利用工具类的方法commons-io-1.4.rar  
        IOUtils.copy(is, os);  
        //关流  
        os.close();  
        is.close();  
    \}  
          
    /\*\*  
     \* @see HttpServlet\#doPost(HttpServletRequest request, HttpServletResponse response)  
     \*/  
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException \{  
        // TODO Auto-generated method stub  
        doGet(request, response);  
    \}