有关servlet实现文件下载

废话不多说，上代码

 1 package com.mlq.servlet;
 2 
 3 import com.sun.net.httpserver.HttpsServer;
 4 
 5 import javax.servlet.ServletException;
 6 import javax.servlet.ServletOutputStream;
 7 import javax.servlet.http.HttpServlet;
 8 import javax.servlet.http.HttpServletRequest;
 9 import javax.servlet.http.HttpServletResponse;
10 import java.io.FileInputStream;
11 import java.io.IOException;
12 import java.net.URLEncoder;
13 
14 public class ServletReponseDFile extends HttpServlet {
15     @Override
16     protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
17 //            § 获取现在文件的路径
18 //            § 下载的文件名
19 //            § 设置让浏览器支持我们需要的下载的东西，让URLEncoder.encode编码，否则可能乱码
20 //            § 获取下载文件的输入流
21 //            § 创建缓冲区
22 //            § 获取OutputStream对象
23 //            § =将FileOutputStream流写入到buffer缓冲区
24 //          使用OutputStream，将缓冲区中的数据输出到客户端中
25         String realPath="D:/Javacode/servletWebappDemo2/servletWebappDemo2/src/main/resources/1.jpg";
26         String filename=realPath.substring(realPath.lastIndexOf("/")+1);
27         resp.setHeader("Content-Disposition", "attachment; filename="+ URLEncoder.encode(filename,"utf-8"));
28         FileInputStream in=new FileInputStream(realPath);
29         byte[] bytes=new byte[1024];
30         int len=0;
31         ServletOutputStream out = resp.getOutputStream();
32         while ((len=in.read(bytes))>0){
33             out.write(bytes,0,len);
34         }
35     }
36 
37     @Override
38     protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
39         doPost(req, resp);
40     }
41 }