转自：https://www.jb51.net/article/142736.htm
springMVC默认的解析器里面是没有加入对文件上传的解析的,，使用springmvc对文件上传的解析器来处理文件上传的时需要用springmvc提供的MultipartResolver的申明，又因为CommonsMultipartResolver实现了MultipartResolver接口，所以我们可以在springmvc配置文件中这样配置：
1 <bean id="multipartResolver" 2 class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> 3 <property name="defaultEncoding" value="utf-8" /> 4 <property name="maxUploadSize" value="10485760000" /> 5 <property name="maxInMemorySize" value="40960" /> 6 </bean>
首先引入文件上传所需要的包,commons-logging-*.jar commons-io-*.jar commons-fileupload-*.jar
新建一个JSP页面.
1 <%@ page language="java" contentType="text/html; charset=UTF-8" 2 pageEncoding="UTF-8"%> 3 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 4 <html> 5 <head> 6 <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 7 <title>文件上传</title> 8 </head> 9 <body> 10 <%--<form action="user/fileUpload" method="post" enctype="multipart/form-data">--%> 11 <form action="user/fileUpload" method="post" enctype="multipart/form-data"> 12 <input type="file" name="fileUpload" /> 13 <input type="submit" value="上传" /> 14 </form> 15 </body> 16 </html>
springmvc上传文件的形式有很多,这里我介绍两种.
第一种,看Controller
1 package gd.hz.springmvc.controller; 2 3 import java.io.File; 4 import java.io.IOException; 5 6 import org.springframework.stereotype.Controller; 7 import org.springframework.web.bind.annotation.RequestMapping; 8 import org.springframework.web.bind.annotation.RequestMethod; 9 import org.springframework.web.bind.annotation.RequestParam; 10 import org.springframework.web.multipart.commons.CommonsMultipartFile; 11 import org.springframework.web.servlet.ModelAndView; 12 13 @Controller("userController") 14 @RequestMapping("user") 15 public class UserController { 16 17 // 处理文件上传一 18 @RequestMapping(value = "fileUpload", method = RequestMethod.POST) 19 public ModelAndView fileUpload( 20 @RequestParam("fileUpload") CommonsMultipartFile file) { 21 // 获取文件类型 22 System.out.println(file.getContentType()); 23 // 获取文件大小 24 System.out.println(file.getSize()); 25 // 获取文件名称 26 System.out.println(file.getOriginalFilename()); 27 28 // 判断文件是否存在 29 if (!file.isEmpty()) { 30 String path = "D:/" + file.getOriginalFilename(); 31 File localFile = new File(path); 32 try { 33 file.transferTo(localFile); 34 } catch (IllegalStateException e) { 35 e.printStackTrace(); 36 } catch (IOException e) { 37 e.printStackTrace(); 38 } 39 } 40 return new ModelAndView("dataSuccess"); 41 } 42 }
类CommonsMultipartFile为我们提供了许多对文件处理的方法.例如文件大小,上传文件名称,文件类型,具体用法可以查看spring的文档.transferTo就是将文件输出到指定地方.
文件上传的第二种方法,这种方法比较常用:
1 package gd.hz.springmvc.controller; 2 3 import java.io.File; 4 import java.io.IOException; 5 import java.util.Iterator; 6 7 import javax.servlet.http.HttpServletRequest; 8 9 import org.springframework.stereotype.Controller; 10 import org.springframework.web.bind.annotation.RequestMapping; 11 import org.springframework.web.bind.annotation.RequestMethod; 12 import org.springframework.web.multipart.MultipartFile; 13 import org.springframework.web.multipart.MultipartHttpServletRequest; 14 import org.springframework.web.multipart.commons.CommonsMultipartResolver; 15 16 @Controller("userController") 17 @RequestMapping("user") 18 public class UserController { 19 20 // 处理文件上传二 21 @RequestMapping(value = "fileUpload2", method = RequestMethod.POST) 22 public String fileUpload2(HttpServletRequest request) 23 throws IllegalStateException, IOException { 24 // 设置上下方文 25 CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver( 26 request.getSession().getServletContext()); 27 28 // 检查form是否有enctype="multipart/form-data" 29 if (multipartResolver.isMultipart(request)) { 30 MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest) request; 31 32 Iterator<String> iter = multiRequest.getFileNames(); 33 while (iter.hasNext()) { 34 35 // 由CommonsMultipartFile继承而来,拥有上面的方法. 36 MultipartFile file = multiRequest.getFile(iter.next()); 37 if (file != null) { 38 String fileName = "demoUpload" + file.getOriginalFilename(); 39 String path = "D:/" + fileName; 40 41 File localFile = new File(path); 42 file.transferTo(localFile); 43 } 44 45 } 46 } 47 return "dataSuccess"; 48 } 49 }
MultipartHttpServletRequest提供了更加灵活的方法,可以获取多个文件和文件名,可以遍历获得每个文件.