Servlet的response处理下载_servletutils.getresponse()-优快云博客

本文链接：https://blog.youkuaiyun.com/WXB52112181314/article/details/81710352

实现response处理下载

首先在WebContent下建一个文件夹存放需要下载的资源，导入Commons-io-24.jar，然后在建一个jsp文件和Servlet类，

import java.io.IOException;
import java.io.InputStream;
import java.util.UUID;

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

import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils;

/*
 * response处理下载
 */
public class Servlet4 extends HttpServlet {
	@Override
	protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
		doGet(req, resp);
	}

	@Override
	protected void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		// 指定下载的文件路径
		String path = "/down/servletbase.rar";
		// 创建对象
		ServletContext context = this.getServletContext();
		// System.out.println(context);
		// 获得一个输入流
		InputStream in = context.getResourceAsStream(path);
		// 响应输出流
		ServletOutputStream out = response.getOutputStream();
		// 1、以文件名为下载的文件名(可修改)
		// String downname = FilenameUtils.getName(path);
		// 2、修改下载的文件名(uuid)
		String downname = UUID.randomUUID().toString() + "." + FilenameUtils.getExtension(path);
		// System.out.println(downname);
		// 控制浏览器以下载方式打开;
		response.setHeader("Content-Disposition", "attachment;filename=" + downname);
		// 实现下载 服务器---复制---客户端
		IOUtils.copy(in, out);
		// 关闭流
		in.close();
		out.close();
	}

}

down.jsp文件

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
进入下载界面
<a href="down/GoodsSystem.zip">下载1...</a>
<a href="down/1.jpg">下载图片...</a>
<a href="down/1.txt">下载文档...</a>
<a href="/servletproject3/Servlet4">Servlet下载...</a>
</body>
</html>

然后在web.xml中发布创建的Servlet就可实现下载了