• 文件下载与上传


    jsp

    复制代码
    <style type="text/css">
            form{
                margin:0px auto; 
                border:1px solid red;
                500px;
                padding:20px;
            }
        </style>
      </head>
      
      <body>
       <form action="${pageContext.request.contextPath }/frist.do" method="post" enctype="multipart/form-data">
           <h1>文件上传</h1>
           文件:<input type="file" name="uploadFile"/><br/>
           文件:<input type="file" name="uploadFile"/><br/>
           文件:<input type="file" name="uploadFile"/><br/>
           <input type="submit" value="上传">
       </form>
      </body>
    复制代码

    单文件上传 

    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>
      <!-- ================spring mvc 适配器================ -->  
      <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>
        <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(多文件上传与单文件上传配置相同下面介绍一下不同的地方)

    标记为红色的字段为多文件上传 与单文件上传的区别

     
     @RequestMapping(value="/firstdown.do")
    public String doFirst(@RequestParam MultipartFile[] uploadFile,HttpSession session)throws Exception{
        for (MultipartFile item : uploadFile) {
             
            if(item.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=item.getOriginalFilename();
                if(fileName.endsWith(".jpg")||fileName.endsWith(".JPG")){
                    //03.路径拼接
                    File file = new File(path,fileName);
                    item.transferTo(file);
                }
                return "welcome.jsp";
            }
        }
        return "error.jsp";
    }

    文件下载

    1
    @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(); 
        
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  • 原文地址:https://www.cnblogs.com/liang67732116/p/6270422.html
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