SpringMVC通过MultipartResolver（多部件解析器）对象实现对文件上传的支持。
MultipartResolver是一个接口对象，需要通过它的实现类CommonsMultipartResolver来完成文件的上传工作。
1.上传需要jar包 commons-fileupload.jar commons-io.jar
2.使用MultipartResolver对象，在XML中配置Bean.
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.3.xsd"> <context:annotation-config/> <context:component-scan base-package="com.wxy.controller"/> <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"></property> <property name="suffix" value=".jsp"></property> </bean> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="defaultEncoding" value="UTF-8" /> <property name="maxUploadSize" value="2097152" /> </bean> </beans>
3.fileUpload.jsp上传页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>文件上传</title> <script> <%--判断是否填写上传人并已经选择上传文件--%> function check() { var name = document.getElementById("name").value(); var name = document.getElementById("file").value(); if(name==""){ alert("请填写上传人"); return false; } if(file.length==0||file==""){ alert("请选择上传文件"); return false; } return true; } </script> </head> <body> <%--enctype="multipart/form-data"采用二进制流处理表单数据--%> <form action="${pageContext.request.contextPath}/fileUpload.action" method="post" enctype="multipart/form-data" onsubmit="return check()"> 上传人：<input id="name" type="text" name="name"/><br/> 请选择文件：<input id="file" type="file" name="uploadfile" multiple="multiple"/><br/> <%--multiple属性选择多个文件上传--%> <input type="submit" value="文件上传" /> </form> </body> </html>
4.fileDownload.jsp下载页面
<%@ page contentType="text/html;charset=UTF-8" language="java" pageEncoding="UTF-8" %> <%@ page import="java.net.URLEncoder" %> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>文件下载</title> </head> <body> <a href="${pageContext.request.contextPath}/download.action?filename=<%=URLEncoder.encode("图像.txt","UTF-8")%>">文件下载</a> </body> </html>
5.FileUploadAndDownloadController.java文件上传和下载控制器类
package com.wxy.controller; import org.apache.commons.io.FileUtils; import org.springframework.http.HttpHeaders; import org.springframework.http.HttpStatus; import org.springframework.http.MediaType; import org.springframework.http.ResponseEntity; 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.net.URLEncoder; import java.util.List; import java.util.UUID; @Controller("controller") public class FileUploadAndDownloadController { @RequestMapping("/tofileUpload") public String toupload(){ return "fileUpload"; } @RequestMapping("/tofiledownload") public String todownload(){ return "download"; } @RequestMapping("/fileUpload.action") public String handleFormUpload(@RequestParam("name") String name, @RequestParam("uploadfile") List<MultipartFile> uploadfile, HttpServletRequest request) { if (!uploadfile.isEmpty() && uploadfile.size() > 0) { for (MultipartFile file : uploadfile) { String originalFilename = file.getOriginalFilename(); String dirPath = request.getServletContext().getRealPath("/upload/"); File filePath = new File(dirPath); if (!filePath.exists()) { filePath.mkdirs(); } String newFilename = name +"_" + originalFilename; try { file.transferTo(new File(dirPath + "_"+newFilename)); } catch (Exception e) { e.printStackTrace(); return "error"; } } return "success"; } else { return "error"; } } @RequestMapping("/download.action") public ResponseEntity<byte[]> filedownload(HttpServletRequest request,String filename) throws Exception{ String path = request.getServletContext().getRealPath("/upload"); File file = new File(path+File.separator+filename); filename = this.getFilename(request,filename); HttpHeaders headers = new HttpHeaders(); headers.setContentDispositionFormData("attachment",filename); headers.setContentType(MediaType.APPLICATION_OCTET_STREAM); return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),headers, HttpStatus.OK); } public String getFilename(HttpServletRequest request,String filename) throws Exception{ String[] IEBrowserKeyWord = {"MSIE","Trident","Edge"}; String userAgent = request.getHeader("User-Agent"); for(String keyWord:IEBrowserKeyWord){ if(userAgent.contains(keyWord)){ return URLEncoder.encode(filename,"UTF-8"); } } return new String(filename.getBytes("UTF-8"),"ISO-8859-1"); } }