了解SpringMVC的上传和下载

< beans xmlns = "http://HdhCmsTestspringframework.org/schema/beans"

        xmlns:xsi = "http://HdhCmsTestw3.org/2001/XMLSchema-instance"

        xmlns:context = "http://HdhCmsTestspringframework.org/schema/context"

        xmlns:aop = "http://HdhCmsTestspringframework.org/schema/aop"

        xmlns:tx = "http://HdhCmsTestspringframework.org/schema/tx"

        xmlns:mvc = "http://HdhCmsTestspringframework.org/schema/mvc"

        xsi:schemaLocation="http://HdhCmsTestspringframework.org/schema/beans

     https://HdhCmsTestspringframework.org/schema/beans/spring-beans.xsd

     http://HdhCmsTestspringframework.org/schema/context

     https://HdhCmsTestspringframework.org/schema/context/spring-context.xsd

     http://HdhCmsTestspringframework.org/schema/aop

     https://HdhCmsTestspringframework.org/schema/aop/spring-aop.xsd

     http://HdhCmsTestspringframework.org/schema/tx

     https://HdhCmsTestspringframework.org/schema/tx/spring-tx.xsd

     http://HdhCmsTestspringframework.org/schema/mvc

     https://HdhCmsTestspringframework.org/schema/mvc/spring-mvc.xsd">

     <!--    开启ioc注解开启扫描-->

     < context:component-scan base-package = "cn.hp" ></ context:component-scan >

     <!--    开启mvc的注解扫描  里面有个转换服务器-->

     < mvc:annotation-driven ></ mvc:annotation-driven >

     <!--    将视图解析器 交给spring-->

     < bean id = "resolver" class = "org.springframework.web.servlet.view.InternalResourceViewResolver" >

         <!--        <property name="prefix" value="/WEB-INF/pages/"></property>-->

         < property name = "prefix" value = "/" ></ property >

         < property name = "suffix" value = ".jsp" ></ property >

     </ bean >

     <!--    配置一个bean 让他支持文件上传-->

     < bean id = "multipartResolver" class = "org.springframework.web.multipart测试数据mons.CommonsMultipartResolver" >

         <!--        俩属性 name="defaultEncoding" 编码格式utf-8

                     name="maxUploadSize" 文件上传最大 值 100M

         -->

         < property name = "defaultEncoding" value = "utf-8" ></ property >

         < property name = "maxUploadSize" value = "10240000" ></ property >

     </ bean >

</ beans >

<? xml version = "1.0" encoding = "UTF-8" ?>

< web-app xmlns = "http://xmlns.jcp.org/xml/ns/javaee"

          xmlns:xsi = "http://HdhCmsTestw3.org/2001/XMLSchema-instance"

          xsi:schemaLocation = "http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"

          version = "4.0" >

     < servlet >

         < servlet-name >dispatcherServlet</ servlet-name >

         < servlet-class >org.springframework.web.servlet.DispatcherServlet</ servlet-class >

         <!-- 初始化时加载springmvc配置文件 -->

         < init-param >

             < param-name >contextConfigLocation</ param-name >

             < param-value >classpath:*.xml</ param-value >

         </ init-param >

     </ servlet >

     < servlet-mapping >

         < servlet-name >dispatcherServlet</ servlet-name >

         < url-pattern >*.do</ url-pattern >

     </ servlet-mapping >

     < filter >

         < filter-name >fileEncoding</ filter-name >

         < filter-class >org.springframework.web.filter.CharacterEncodingFilter</ filter-class >

         < init-param >

             < param-name >Encoding</ param-name >

             < param-value >UTF-8</ param-value >

         </ init-param >

     </ filter >

     < filter-mapping >

         < filter-name >fileEncoding</ filter-name >

         < url-pattern >/*</ url-pattern >

     </ filter-mapping >

</ web-app >

package cn.hp.controller;

import org.apache测试数据mons.io.FileUtils;

import org.springframework.beans.factory.annotation.Autowired;

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.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import java.io.File;

import java.io.IOException;

import java.io.UnsupportedEncodingException;

import java.util.Date;

import java.util.Random;

@Controller

public class FileUploadController {

     @RequestMapping (value= "upload.do" )

     public String upload(MultipartFile file[], HttpServletRequest request) throws IOException {

         //1.获取上传文件路径

         String path = request.getServletContext().getRealPath( "/upload" );

         for ( int i = 0 ;i<file.length;i++) {

             //2.拿到上传的文件名

             String name = file[i].getOriginalFilename();

             //3.改名，把用户上传的文件进行改名操作

             String newNmae = new Date().getTime() + new Random().nextInt( 999999 ) + name;

             //4.实例化File类的对象加载上传的路径和文件

             File f = new File(path + newNmae);

             //5. MultipartFile里面的方法把这个路径的文件写入过去

             file[i].transferTo(f);

         }

         return "success" ;

     }

     @RequestMapping (value= "download.do" )

     public ResponseEntity< byte []> download( @RequestParam ( "fileName" ) String fileName,HttpServletRequest request) throws IOException {

         //1.下载路径

         String path = request.getServletContext().getRealPath( "/download/" );

         //2.实例化File类的对象加载下载的路径和文件

         File f= new File(path+fileName);

         //3.转格式

         String newName = new String(fileName.getBytes( "utf-8" ), "iso8859-1" );

         //4.转流

         HttpHeaders hh = new HttpHeaders();

         hh.setContentDispositionFormData( "attachment" ,newName);

         hh.setContentType(MediaType.APPLICATION_OCTET_STREAM);

         //5.相应发送

         return   new ResponseEntity< byte []>(FileUtils.readFileToByteArray(f),hh, HttpStatus.CREATED);

     }

}

<%@ page contentType= "text/html;charset=UTF-8" language= "java" %>

<html>

<head>

     <title>Title</title>

</head>

<body>

<%--如果说表单有文件上传的功能，那么表达就要设置这个属性--%>

<form action= "upload" method= "post" enctype= "multipart/form-data" >

     文件上传<input type= "file" name= "file" /><br/>

     文件上传<input type= "file" name= "file" /><br/>

     文件上传<input type= "file" name= "file" /><br/>

     <input type= "submit" value= "确定" />

</form>

<a href= "download/自我介绍模板.docx" >下载文件</a>

<a href= "download/10.png" >下载文件</a>

<a href= "download/4.jpg" >下载文件1</a>

<a href= "download.do?fileName=新建文本文档.txt" >下载文件2</a>

<a href= "download/新建文本文档.txt" >下载文件3</a>

</body>

</html>

<%@ page contentType= "text/html;charset=UTF-8" language= "java" %>

<html>

<head>

     <title>Title</title>

</head>

<body>

上传成功

</body>

</html>