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.使用MultipartResolver对象，在XML中配置Bean.
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:context="http://www.springframework.org/schema/context" 5 xsi:schemaLocation="http://www.springframework.org/schema/beans 6 http://www.springframework.org/schema/beans/spring-beans-4.3.xsd 7 http://www.springframework.org/schema/context 8 http://www.springframework.org/schema/context/spring-context-4.3.xsd"> 9 <context:annotation-config/> 10 <context:component-scan base-package="com.wxy.controller"/> 11 <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver"> 12 <property name="prefix" value="/WEB-INF/jsp/"></property> 13 <property name="suffix" value=".jsp"></property> 14 </bean> 15 <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> 16 <property name="defaultEncoding" value="UTF-8" /> 17 <property name="maxUploadSize" value="2097152" /> 18 </bean> 19 </beans>
2.fileUpload.jsp上传页面
1 <%@ page contentType="text/html;charset=UTF-8" language="java" %> 2 <html> 3 <head> 4 <title>文件上传</title> 5 <script> 6 <%--判断是否填写上传人并已经选择上传文件--%> 7 function check() { 8 var name = document.getElementById("name").value(); 9 var name = document.getElementById("file").value(); 10 if(name==""){ 11 alert("请填写上传人"); 12 return false; 13 } 14 if(file.length==0||file==""){ 15 alert("请选择上传文件"); 16 return false; 17 } 18 return true; 19 } 20 </script> 21 </head> 22 <body> 23 <%--enctype="multipart/form-data"采用二进制流处理表单数据--%> 24 <form action="${pageContext.request.contextPath}/fileUpload.action" method="post" enctype="multipart/form-data" onsubmit="return check()"> 25 上传人：<input id="name" type="text" name="name"/><br/> 26 请选择文件：<input id="file" type="file" name="uploadfile" multiple="multiple"/><br/> 27 <%--multiple属性选择多个文件上传--%> 28 <input type="submit" value="文件上传" /> 29 </form> 30 </body> 31 </html>
3.fileDownload.jsp下载页面
1 <%@ page contentType="text/html;charset=UTF-8" language="java" pageEncoding="UTF-8" %> 2 <%@ page import="java.net.URLEncoder" %> 3 <html> 4 <head> 5 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 6 <title>文件下载</title> 7 </head> 8 <body> 9 <a href="${pageContext.request.contextPath}/download.action?filename=<%=URLEncoder.encode("图像.txt","UTF-8")%>">文件下载</a> 10 </body> 11 </html>
4.FileUploadAndDownloadController.java文件上传和下载控制器类
1 package com.wxy.controller; 2 3 import org.apache.commons.io.FileUtils; 4 import org.springframework.http.HttpHeaders; 5 import org.springframework.http.HttpStatus; 6 import org.springframework.http.MediaType; 7 import org.springframework.http.ResponseEntity; 8 import org.springframework.stereotype.Controller; 9 import org.springframework.web.bind.annotation.RequestMapping; 10 import org.springframework.web.bind.annotation.RequestParam; 11 import org.springframework.web.multipart.MultipartFile; 12 13 import javax.servlet.http.HttpServletRequest; 14 import java.io.File; 15 import java.net.URLEncoder; 16 import java.util.List; 17 import java.util.UUID; 18 19 @Controller("controller") 20 public class FileUploadAndDownloadController { 21 @RequestMapping("/tofileUpload") 22 public String toupload(){ 23 return "fileUpload"; 24 } 25 @RequestMapping("/tofiledownload") 26 public String todownload(){ 27 return "download"; 28 } 29 @RequestMapping("/fileUpload.action") 30 public String handleFormUpload(@RequestParam("name") String name, 31 @RequestParam("uploadfile") List<MultipartFile> uploadfile, HttpServletRequest request) { 32 if (!uploadfile.isEmpty() && uploadfile.size() > 0) { 33 for (MultipartFile file : uploadfile) { 34 String originalFilename = file.getOriginalFilename(); 35 String dirPath = request.getServletContext().getRealPath("/upload/"); 36 File filePath = new File(dirPath); 37 if (!filePath.exists()) { 38 filePath.mkdirs(); 39 } 40 41 String newFilename = name +"_" + originalFilename; 42 try { 43 file.transferTo(new File(dirPath + "_"+newFilename)); 44 } catch (Exception e) { 45 e.printStackTrace(); 46 return "error"; 47 } 48 } 49 return "success"; 50 } else { 51 return "error"; 52 } 53 } 54 @RequestMapping("/download.action") 55 public ResponseEntity<byte[]> filedownload(HttpServletRequest request,String filename) throws Exception{ 56 String path = request.getServletContext().getRealPath("/upload"); 57 File file = new File(path+File.separator+filename); 58 filename = this.getFilename(request,filename); 59 HttpHeaders headers = new HttpHeaders(); 60 headers.setContentDispositionFormData("attachment",filename); 61 headers.setContentType(MediaType.APPLICATION_OCTET_STREAM); 62 return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),headers, HttpStatus.OK); 63 } 64 public String getFilename(HttpServletRequest request,String filename) throws Exception{ 65 String[] IEBrowserKeyWord = {"MSIE","Trident","Edge"}; 66 String userAgent = request.getHeader("User-Agent"); 67 for(String keyWord:IEBrowserKeyWord){ 68 if(userAgent.contains(keyWord)){ 69 return URLEncoder.encode(filename,"UTF-8"); 70 } 71 } 72 return new String(filename.getBytes("UTF-8"),"ISO-8859-1"); 73 } 74 }