Spring mvc文件上传与下载

文件上传

SpringMVC实现文件上传,需要再添加两个jar包。一个是文件上传的jar包,一个是其所依赖的IO包。这两个jar包,均在Spring支持库的org.apache.commons中。

单文件上传

    jsp页面

<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    <style type="text/css">
       form{
         margin:0px auto;
         border:1px solid red;
         500px;
         padding:20px;
       }
    </style>
    <title></title>
  </head>
  
  <body>
    <form action="${pageContext.request.contextPath }/first.do" method="post" enctype="multipart/form-data">
    <h1>文件上传</h1>
                 文件:<input type="file" name="uploadFile"/><br/>
       <input type="submit" value="上传"/>
    </form>
  </body>
</html>

通过对文件的大小来判断是否有文件

通过文件的类型来判断是否是允许

@Controller
public class MyController {
    @RequestMapping(value="/frist.do", method=RequestMethod.POST)
    public String doFirst(HttpSession session,MultipartFile uploadFile)throws Exception{
        if(uploadFile.getSize()>0){
            //02.获取前半部分路径,jiangWebRoot下一个名称为images文件夹  转换成绝对路径
            String path = session.getServletContext().getRealPath("/upload");
            //01.获取文件名作为保存到服务器的文件名称
            String fileName=uploadFile.getOriginalFilename();
            if(fileName.endsWith(".jpg")||fileName.endsWith(".JPG")){
                //03.路径拼接
                File file = new File(path,fileName);
                uploadFile.transferTo(file);
            }
            return "welcome.jsp";
        }
        return "error.jsp";
    }

   applicationContext.xml配置

<?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:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        ">
 
    <!-- 配置包扫描器 -->
    <context:component-scan base-package="cn.controller"></context:component-scan>
 
 
    <bean id="multipartResolver"
        class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <property name="defaultEncoding" value="utf-8"></property><!-- 客户端发送数据的编码 -->
        <property name="maxUploadSize" value="5242880"></property><!-- 上传文件的大小 -->
        <!-- <property name="uploadTempDir" value="/upload"></property> -->
    </bean>
    <!-- mvc注解驱动 -->
    <mvc:annotation-driven />
 
</beans>

  web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	xmlns="http://java.sun.com/xml/ns/javaee" 
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
	http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
  <display-name></display-name>	
  
  <!-- 编码过滤器 -->
  <filter>
    <filter-name>CharacterEncoding</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>CharacterEncoding</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>


  <!-- 配置中央调度器 -->
  <servlet>
    <servlet-name>springmvc</servlet-name> 
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> 
    <init-param>
	    <param-name>contextConfigLocation</param-name>
	    <param-value>classpath:applicationContext.xml</param-value>
    </init-param>
    <!-- TOmcat启动的时候,Servlet对象就存储到内存 正整数 -->
    <load-on-startup>1</load-on-startup>
  </servlet>
  
  <servlet-mapping>
    <servlet-name>springmvc</servlet-name>
    <url-pattern>*.do</url-pattern>
  </servlet-mapping>
 
  
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

  多文件上传

 文件下载

@RequestMapping(value="/first.do")
<br> public static void download(HttpServletRequest request, 
            HttpServletResponse response, String storeName, String contentType
           ) throws Exception { 
         
        request.setCharacterEncoding("UTF-8"); 
        BufferedInputStream bis = null; 
        BufferedOutputStream bos = null; 
   
        //获取项目根目录
        String ctxPath = request.getSession().getServletContext() 
                .getRealPath(""); 
         
        //获取下载文件露肩
        String downLoadPath = ctxPath+"/uploadFile/"+ storeName; 
   
        //获取文件的长度
        long fileLength = new File(downLoadPath).length(); 
 
        //设置文件输出类型
        response.setContentType("application/octet-stream"); 
        response.setHeader("Content-disposition", "attachment; filename=" 
                + new String(storeName.getBytes("utf-8"), "ISO8859-1"));
        //设置输出长度
        response.setHeader("Content-Length", String.valueOf(fileLength)); 
        //获取输入流
        bis = new BufferedInputStream(new FileInputStream(downLoadPath)); 
        //输出流
        bos = new BufferedOutputStream(response.getOutputStream()); 
        byte[] buff = new byte[2048]; 
        int bytesRead; 
        while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) { 
            bos.write(buff, 0, bytesRead); 
        } 
        //关闭流
        bis.close(); 
        bos.close(); 
    } 

  JSP页面

<a href="./downloadFile/download" >下载</a> 

  

原文地址:https://www.cnblogs.com/yangronglin/p/6270427.html