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springMVC實現(xiàn)文件上傳和下載

更新時間：2021年08月10日 15:24:38 作者：奕銘呀

這篇文章主要為大家詳細介紹了springMVC實現(xiàn)文件上傳和下載，文中示例代碼介紹的非常詳細，具有一定的參考價值，感興趣的小伙伴們可以參考一下

本文實例為大家分享了springMVC實現(xiàn)文件上傳和下載的具體代碼，供大家參考，具體內(nèi)容如下

1準(zhǔn)備工作

web.xml文件導(dǎo)入DispatcherServlet，CharacterEncodingFilter

<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>/</url-pattern>
    </servlet-mapping>


    <filter>
        <filter-name>encoding</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>encoding</filter-name>
        <url-pattern>/*</url-pattern>
</filter-mapping>

前端測試頁面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
  <head>
    <title>$Title$</title>
  </head>
  <body>
  <%--  必須將表單的method設(shè)置為POST--%>
  <%--  設(shè)置enctype屬性為multipart/form-data，二進制傳遞數(shù)據(jù)--%>
  <form action="${pageContext.request.contextPath}/upload2" enctype="multipart/form-data" method="post">
    <input type="file" name="file"/>
    <input type="submit" value="upload">
  </form>
  <br/>
  <a href="${pageContext.request.contextPath}/download" rel="external nofollow" >點擊下載</a>
  </body>
</html>

spring配置文件applicationContext.xml

<?xml version="1.0" encoding="UTF8"?>
<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: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
       https://www.springframework.org/schema/context/spring-context.xsd
       http://www.springframework.org/schema/mvc
       https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!-- 自動掃描指定的包，下面所有注解類交給IOC容器管理，根據(jù)自己的項目掃描包 -->
    <context:component-scan base-package="com.zky.controller"/>
    <!-- 注解驅(qū)動 -->
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                        <property name="failOnEmptyBeans" value="false"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>
    <!-- 靜態(tài)資源過濾-->
    <mvc:default-servlet-handler/>
    <!-- 視圖解析器 -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"
          id="internalResourceViewResolver">
        <!-- 前綴 -->
        <property name="prefix" value="/WEB-INF/jsp/" />
        <!-- 后綴 -->
        <property name="suffix" value=".jsp" />
    </bean>

    <!--文件上傳配置-->
    <bean id="multipartResolver"  class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
        <!-- 請求的編碼格式，必須和jSP的pageEncoding屬性一致，以便正確讀取表單的內(nèi)容，默認為ISO-8859-1 -->
        <property name="defaultEncoding" value="utf-8"/>
        <!-- 上傳文件大小上限，單位為字節(jié)（10485760=10M） -->
        <property name="maxUploadSize" value="10485760"/>
        <property name="maxInMemorySize" value="40960"/>
    </bean>
</beans>

2.文件上傳

controller

package com.zky.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.commons.CommonsMultipartFile;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;

@Controller
public class FileController {
    //@RequestParam("file") 將name=file控件得到的文件封裝成CommonsMultipartFile 對象
    //批量上傳CommonsMultipartFile則為數(shù)組即可
    @RequestMapping("/upload")
    public String fileUpload(@RequestParam("file") CommonsMultipartFile file , HttpServletRequest request) throws IOException {

        //獲取文件名 : file.getOriginalFilename();
        String uploadFileName = file.getOriginalFilename();

        //如果文件名為空，直接回到首頁！
        if ("".equals(uploadFileName)){
            return "redirect:/index.jsp";
        }
        System.out.println("上傳文件名 : "+uploadFileName);

        //上傳路徑保存設(shè)置
        String path = request.getServletContext().getRealPath("/upload");
        //如果路徑不存在，創(chuàng)建一個
        File realPath = new File(path);
        if (!realPath.exists()){
            realPath.mkdir();
        }
        System.out.println("上傳文件保存地址："+realPath);

        InputStream is = file.getInputStream(); //文件輸入流
        OutputStream os = new FileOutputStream(new File(realPath,uploadFileName)); //文件輸出流

        //讀取寫出
        int len=0;
        byte[] buffer = new byte[1024];
        while ((len=is.read(buffer))!=-1){
            os.write(buffer,0,len);
            os.flush();
        }
        os.close();
        is.close();
        return "redirect:/index.jsp";
    }
}

采用file.Transto 來保存上傳的文件

/*
     * 采用file.Transto 來保存上傳的文件
     */
    @RequestMapping("/upload2")
    public String  fileUpload2(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException {

        //上傳路徑保存設(shè)置
        String path = request.getServletContext().getRealPath("/upload");
        File realPath = new File(path);
        if (!realPath.exists()){
            realPath.mkdir();
        }
        //上傳文件地址
        System.out.println("上傳文件保存地址："+realPath);

        //通過CommonsMultipartFile的方法直接寫文件（注意這個時候）
        file.transferTo(new File(realPath +"/"+ file.getOriginalFilename()));

        return "redirect:/index.jsp";
    }

3.文件下載

@RequestMapping(value="/download")
    public String downloads(HttpServletResponse response , HttpServletRequest request) throws Exception{
        //要下載的圖片地址，改為自己圖片路徑,我是下載在我的項目里面的
        String  path = request.getServletContext().getRealPath("/upload");
        //文件名
        String  fileName = "新建文本文檔.txt";

        //1、設(shè)置response 響應(yīng)頭
        response.reset(); //設(shè)置頁面不緩存,清空buffer
        response.setCharacterEncoding("UTF-8"); //字符編碼
        response.setContentType("multipart/form-data"); //二進制傳輸數(shù)據(jù)
        //設(shè)置響應(yīng)頭
        response.setHeader("Content-Disposition",
                "attachment;fileName="+ URLEncoder.encode(fileName, "UTF-8"));

        File file = new File(path,fileName);
        //2、 讀取文件--輸入流
        InputStream input=new FileInputStream(file);
        //3、 寫出文件--輸出流
        OutputStream out = response.getOutputStream();

        byte[] buff =new byte[1024];
        int index=0;
        //4、執(zhí)行 寫出操作
        while((index= input.read(buff))!= -1){
            out.write(buff, 0, index);
            out.flush();
        }
        out.close();
        input.close();
        return null;
    }

以上就是本文的全部內(nèi)容，希望對大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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