Java笔记之SpringMVC(五):上传文件
0.说在前面
1.导入jar包commons-io-x.x.jar和commons-fileupload-x.x.jar
我这里使用的是commons-io-2.4.jar和commons-fileupload-1.4.jar
2.新建fileupload.jsp和show.jsp页面
fileupload.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>文件上传</title> </head> <body> <form action="fileupload.action" method="post" enctype="multipart/form-data"> <input type="file" name="myFile"/> <button type="submit">上传</button> </form> </body> </html>
show.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> </head> <body> <img alt="图片" src="upload/${fileName }"> </body> </html>
3.springmvc.xml配置文件上传解析器
<?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:mvc="http://www.springframework.org/schema/mvc" xmlns:context="http://www.springframework.org/schema/context" xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd"> <!-- 开启注解扫描, base-package配置Controller所在的基础包--> <context:component-scan base-package="com.springmvc.demo.controller"></context:component-scan> <!-- 配置视图解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"></property> <property name="suffix" value=".jsp"></property> </bean> <!-- 配置文件上传解析器,设置最大文件大小为10M(10*1024*1024) --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="maxUploadSize" value="10485760"></property> </bean> </beans>
4.新建FileUploadController类,其中包含初始化跳转到fileupload.jsp的方法(initFileUploadPage)和文件上传的方法(fileUpload)
package com.springmvc.demo.controller; import java.io.File; import java.io.IOException; import javax.servlet.http.HttpServletRequest; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.multipart.MultipartFile; @Controller public class FileUploadController { @RequestMapping("/initFileUploadPage.action") public String initFileUploadPage(){ return "fileupload"; } @RequestMapping("/fileupload.action") public String fileUpload(HttpServletRequest request,MultipartFile myFile){ //获取上传文件的原文件名 String fileName = myFile.getOriginalFilename(); String basePath = request.getServletContext().getRealPath("/upload"); File destFile=new File(basePath, fileName); try { myFile.transferTo(destFile); } catch (IllegalStateException e) { e.printStackTrace(); } catch (IOException e) { e.printStackTrace(); } request.setAttribute("fileName", fileName); return "show"; } }
5.访问http://localhost:8080/springmvc_demo/initFileUploadPage.action,跳转到fileupload.jsp页面,选择了桌面上的一张图片
点击上传按钮进行文件的上传和页面的跳转
6.说明
(1).这里上传的是图片,文件自然也是不在话下的,主要是注意文件的大小,可以在springmvc.xml中的上传文件解析器中进行文件大小的配置,这里配置的是10M;
(2).这里将图片上传到了项目部署的环境上的upload文件夹中,这个目的路径根据需要自定义;
(3).为了避免同一个文件的多次上传互相覆盖或者文件同名问题,可以将文件名进行自定义,使用UUID或者加上微秒/纳秒的时间字符串都可以;
(4).提交包含文件的表单数据时,form表单上的enctype属性值要设置为multipart/form-data;
(5).SpringMVC返回视图信息时,可以在ModelAndView中设置视图名称,也可以直接返回一个视图名称字符串,都是可以的,这里就是使用的字符串,将信息放在了request作用域中;
