第六天:SpringMVC文件上传和下载(代码篇)
上传:
前端:
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>上传</title>
</head>
<body>
<%-- multiple="multiple" 多选 --%>
<form action="${pageContext.request.contextPath}/demo3001" method="post" enctype="multipart/form-data">
<input type="file" name="fileInfo" multiple="multiple">
<button>提交</button>
</form>
</body>
</html>
后端:
package com.hxh.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.multipart.MultipartFile; import javax.servlet.http.HttpServletRequest; import java.io.File; import java.io.IOException; /* 文件上传: 1.form表单提交格式为post enctype="multipart/form-data" 2.设置上传下载解析器 + web.xml也要设置上传下载环境 3.MultiparFile 接收资源文件 */ @Controller public class FileUpCoantroller { /* demo3001 步骤: 1.接收上传对象 2.创建 路径资源 对象 3.将接收到的资源对象 复制到 路径资源对象上面去 坑 : 使用 MultipartFile 必须加上一个注解@RequestParam */ @RequestMapping("demo3001") public String demo3001(@RequestParam MultipartFile[] fileInfo, HttpServletRequest request) throws IOException { for (MultipartFile mm : fileInfo) { // 获取img路径 String realPath = request.getSession().getServletContext().getRealPath("/img"); // 得到资源名称 String fileInfoName = mm.getOriginalFilename(); // 路径资源对象 File file = new File(realPath, fileInfoName); // 把接收到的资源对象 复制到路径资源对象上面去 mm.transferTo(file); System.out.println("--上传成功--"); } return "demo1002"; } }
下载:
前端:
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>下载</title> <script type="text/javascript" src="js/jquery.js"></script> <script type="text/javascript"> $(function(){ function dowload(Obj){ window.location.href = "fileDownLoad?fileName="+Obj; } }) </script> </head> <body> <img src="4.jpg" href="javascript:dowload(this.val)"> </body> </html>
后端:
package com.hxh.controller; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import javax.servlet.ServletOutputStream; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.net.URL; import java.net.URLEncoder; @Controller public class FileDownLoadController { /* 下载 */ @RequestMapping("fileDownLoad") public void fileDownLoad(String fileName , HttpServletRequest request , HttpServletResponse response) throws IOException { // 设置浏览器的头 为下载模式 response.setHeader("content-disposition","attachment;filename=" + URLEncoder.encode(fileName,"UTF-8")); // 获取资源名称(图片名称)String fileName // 获取本地资源路径 String realPath = request.getSession().getServletContext().getRealPath("/img"); // 拼接出一个虚拟的资源对象 File file = new File(realPath, fileName); // 想:将此图片放到浏览器 ServletOutputStream os = response.getOutputStream(); int len = -1; byte[] b = new byte[1024]; FileInputStream fis = new FileInputStream(file); while ((len = fis.read(b))!= -1){ os.write(b,0,len); os.flush(); } fis.close(); os.close(); } }
