上传文件和下载 | 易学教程

多文件上传

第一步：架包

第二步

package cn.happy.controller;

import java.io.File;
import java.io.IOException;

import javax.servlet.http.HttpSession;

import org.apache.commons.io.FileUtils;
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;


@Controller
public class FirstController {

      @RequestMapping("/second.do")
  public String doFirst(@RequestParam MultipartFile[] upload,HttpSession session){
        String dirctory = session.getServletContext().getRealPath("/upload");
        for (MultipartFile item : upload) {
            
            //2.文件名称
            String filename = item.getOriginalFilename();
            //加判定，拦截
            if (filename.endsWith(".jpg")||filename.endsWith(".png")) {

                //3.做保存
                File file=new File(dirctory,filename);
                try {
                    item.transferTo(file);
                }  catch (Exception e) {
                    e.printStackTrace();
                }
            }
            
        }
        return "/success.jsp";
      }
    

    
    @RequestMapping("/first.do")
    /**
     * 
     * @param upload   从客户端浏览上传过来的文件对象
     * @return
     */
    public String doFirst(MultipartFile upload,HttpSession session){
        //save到server上的一个具体的文件夹中。

        if (upload.getSize()>0) {
            //1.物理文件夹  
            String dirctory = session.getServletContext().getRealPath("/upload");
            //2.文件名称
            String filename = upload.getOriginalFilename();
            //加判定，拦截
            if (filename.endsWith(".jpg")||filename.endsWith(".png")) {

                //3.做保存
                File file=new File(dirctory,filename);
                try {
                    upload.transferTo(file);
                }  catch (Exception e) {
                    e.printStackTrace();
                }
            }
            
            return "/welcome.jsp";
        }
        else {
            return "/index.jsp";
        }
    }
}

第三步：配置文件

<?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.happy.controller"></context:component-scan>
       
       <!-- 文件上传解析器 -->
       <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
         <property name="defaultEncoding" value="utf-8"></property>
         <property name="maxUploadSize" value="500000000"></property>
       </bean>
       
       <!-- 需要配置注解驱动 -->
       <mvc:annotation-driven/>
</beans>

第四步：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>

第五步：多文件上传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%>">
    
    <title></title>
    <script type="text/javascript" src="js/jquery-1.8.3.js"></script>
   
  </head>
  
  <body>
    <h1>多文件上传</h1>
    <form action="${pageContext.request.contextPath }/second.do" method="post" enctype="multipart/form-data">
               文件1   <input type="file" name="upload"/>
               文件2   <input type="file" name="upload"/>
               <input type="submit"/>
    </form>
  </body>
</html>

文件下载

package cn.happy.controller;

import java.io.File;
import java.io.IOException;

import org.apache.commons.io.FileUtils;
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;
@Controller
public class DownFile {
    @RequestMapping(value="/download.do")
     public ResponseEntity<byte[]> download() throws IOException {    
         
            File file=new File("D:\\hehe.jpg");  
            HttpHeaders headers = new HttpHeaders();    
            String fileName=new String("你好.jpg".getBytes("UTF-8"),"iso-8859-1");//为了解决中文名称乱码问题  
            headers.setContentDispositionFormData("attachment", fileName);   
            headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);   
            return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),headers, HttpStatus.CREATED);    
        }    
    }

jsp

<a href="${pageContext.request.contextPath }/download.do?hehe.png">下载</a>

来源：https://www.cnblogs.com/lizeyang/p/6270389.html

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