在實際開發中，經常遇到要實現文件上傳到服務器端的功能。Spring可以繼承commons-fileupload插件來實現文件上傳的功能。分爲前端JSP編寫和後臺Controller的編寫。
前期準備工作，首先要引入commons-fileupload這個jar包，pom.xml中的配置如下：
<!-- 實現文件上傳，spring集成了這個功能 -->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.2.2</version>
</dependency><!-- 實現文件上傳，這樣一旦某個Request是一個MultipartRequest，它就會首先被MultipartResolver處理，然後再轉發相應的Controller -->
<bean id="multipartResolver"
class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!-- 設置上傳文件的最大尺寸爲1MB -->
<property name="maxUploadSize">
<value>1048576</value>
</property>
</bean>直接上代碼：
1、前端JSP編寫
upload.jsp
<%@ page language="java" pageEncoding="UTF-8"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<script src="resources/js/jquery.js"></script>
</head>
<body>
<form method="post" action="upload.do" enctype="multipart/form-data">
<input type="file" name="file" />
<input type="submit" />
</form>
</body>
</html>
package nju.software.xkxt.web.controller;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.stereotype.Controller;
import org.springframework.ui.ModelMap;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
/**
* @author typ
*
*/
@Controller
public class UploadController {
/**
* 進入下載界面
*
* @param request
* @param response
* @param model
* @return
* @throws IOException
*/
@RequestMapping(value = "upload_enter.do", method = RequestMethod.GET)
public String enter(HttpServletRequest request,
HttpServletResponse response, ModelMap model) throws IOException {
// 進入下載界面
return "upload";
}
/**
* 具體的實現下載功能
*
* @param request
* @param response
* @param model
* @throws IOException
*/
@RequestMapping(value = "upload.do", method = RequestMethod.POST)
public void upload(HttpServletRequest request,
HttpServletResponse response, ModelMap model) throws IOException {
MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
// 得到上傳的文件
MultipartFile mFile = multipartRequest.getFile("file");
// 得到上傳服務器的路徑
String path = request.getSession().getServletContext()
.getRealPath("/WEB-INF/upload/");
// 得到上傳的文件的文件名
String filename = mFile.getOriginalFilename();
byte[] b = mFile.getBytes();
path += "\\" + filename;
// 文件流寫到服務器端
FileOutputStream outputStream = new FileOutputStream(path);
outputStream.write(b);
outputStream.close();
}
}