直接给你能用的代码
<%@ page contentType="text/html;charset=UTF-8" language="java" isELIgnored="false" %> <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <%@ taglib prefix="form" uri="http://www.springframework.org/tags/form" %> <html> <head> <title>文件下载基础</title> </head> <body> <form method="post" action="/RTServler"> 下载测试<input type="text" name="name"> <input type="submit" value="开始下载"> </form> </body> </html>
String path = getServletContext().getRealPath("/img/"+name); 本地路径，我就不说了
package cn.study.servlet; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.net.URLEncoder; /** * Created by ***** on 2018/4/3. */ public class RTServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setCharacterEncoding("UTF-8"); String name = request.getParameter("name");//获取要下载的文件名 System.out.println(name); //第一步：设置响应类型 // response.setContentType("application/force-download");//应用程序强制下载 //第二读取文件 String path = getServletContext().getRealPath("/img/"+name); System.out.println(path); System.out.println("STOP"); InputStream in = new FileInputStream(path); //设置响应头，对文件进行url编码 name = URLEncoder.encode(name, "UTF-8"); response.setHeader("Content-Disposition", "attachment;filename="+name); response.setContentLength(in.available()); //第三步：老套路，开始copy OutputStream out = response.getOutputStream(); byte[] b = new byte[1024]; int len = 0; while((len = in.read(b))!=-1){ out.write(b, 0, len); } out.flush(); out.close(); in.close(); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request,response); } }