服务器端有以下文件：
首先，建一个download.html页面（在点击下载的时候，将要下载的文件名传递给服务器端）：
1 <!DOCTYPE html> 2 <html> 3 <head> 4 <meta charset="UTF-8"> 5 <title>Insert title here</title> 6 </head> 7 <body> 8 <h1>文件下载</h1> 9 <a href="/Zhan_Web_Servlet/filedownload?filename=a.flv">a.flv</a><br> 10 <a href="/Zhan_Web_Servlet/filedownload?filename=a.jpg">a.jpg</a><br> 11 <a href="/Zhan_Web_Servlet/filedownload?filename=a.mp3">a.mp3</a><br> 12 <a href="/Zhan_Web_Servlet/filedownload?filename=a.mp4">a.mp4</a><br> 13 <a href="/Zhan_Web_Servlet/filedownload?filename=a.txt">a.txt</a><br> 14 <a href="/Zhan_Web_Servlet/filedownload?filename=a.zip">a.zip</a> 15 </body> 16 </html>
Servlet配置文件部分：
1 <servlet> 2 <description></description> 3 <display-name>FileDownloadServlet</display-name> 4 <servlet-name>FileDownloadServlet</servlet-name> 5 <servlet-class>demo.FileDownloadServlet</servlet-class> 6 </servlet> 7 <servlet-mapping> 8 <servlet-name>FileDownloadServlet</servlet-name> 9 <url-pattern>/filedownload</url-pattern> 10 </servlet-mapping>
demo包下面的FileDownloadServlet如下：
1 package demo;
2
3 import java.io.FileInputStream;
4 import java.io.IOException;
5 import java.io.InputStream;
6
7 import javax.servlet.ServletException;
8 import javax.servlet.ServletOutputStream;
9 import javax.servlet.http.HttpServlet;
10 import javax.servlet.http.HttpServletRequest;
11 import javax.servlet.http.HttpServletResponse;
12
13 public class FileDownloadServlet extends HttpServlet {
14
15 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
16 //获取要下载文件的名称
17 String fileName = request.getParameter("filename");
18
19 //客户端通过文件的MIME区分下载的文件的类型,所以在服务器端设置文件的MIME类型
20 response.setContentType(this.getServletContext().getMimeType(fileName));
21 //告诉客户端不要直接解析该文件,而是以附件的形式打开(下载)
22 response.setHeader("Content-Disposition", "attachment;filename=" + fileName);
23
24 //获取要下载文件的绝对路径
25 String realPath = this.getServletContext().getRealPath("download/" + fileName);
26
27 ServletOutputStream out = response.getOutputStream();
28 InputStream in = new FileInputStream(realPath);
29 int len = 0;
30 byte[] buffer = new byte[1024];
31 while((len = in.read(buffer)) != -1) {
32 out.write(buffer, 0, len);
33 }
34 in.close();
35 out.close();
36 }
37
38 public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
39 doGet(request, response);
40 }
41 }
启动服务器，访问download.html，界面如下：
点击要下载的文件链接即可下载。
原文地址：https://www.cnblogs.com/AI-xiaocai/p/10464291.html
时间： 2024-10-15 08:03:29