本文实例为大家分享了SpringMVC实现文件上传与下载的具体代码，供大家参考，具体内容如下
0.环境准备
1.maven依赖
<dependencies> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter-api</artifactId> <version>5.7.0</version> <scope>test</scope> </dependency> <!-- servlet依赖 --> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>3.1.0</version> <scope>provided</scope> </dependency> <!-- springMVC依赖 --> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>5.2.6.RELEASE</version> </dependency> <!-- 文件上传的jar包 --> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.8.0</version> </dependency> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.3</version></dependency>
2.springConfig。xml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: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"> <!-- 开启组件扫描 --> <context:component-scan base-package="com.compass.file"></context:component-scan> <!--声明 配置springMVC视图解析器--> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!--前缀：视图文件的路径--> <property name="prefix" value="/WEB-INF/view/" /> <!--后缀：视图文件的扩展名--> <property name="suffix" value=".jsp" /> </bean> <!--读写JSON的支持（Jackson）--> <mvc:annotation-driven /><!-- 配置多媒体解析 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"><!-- 配置字符编码集 --> <property name="defaultEncoding" value="utf-8"> </property><!-- 配置文件上传大小 单位是字节 -1代表没有限制 maxUploadSizePerFile是限制每个上传文件的大小，而maxUploadSize是限制总的上传文件大小 --> <property name="maxUploadSizePerFile" value="-1"> </property> <!-- ，不设置默认不限制总的上传文件大小，这里设置总的上传文件大小不超过1M（1*1024*1024） --> <property name="maxUploadSize" value="1048576"/> </bean></beans>
3.web.xml配置
<?xml version="1.0" encoding="UTF-8"?><web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.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"> <!-- 声明springMvc的核心对象 DispatcherServlet --> <servlet> <servlet-name>web</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:springConfig.xml</param-value> </init-param> <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping> <servlet-name>web</servlet-name> <url-pattern>*.mvc</url-pattern> </servlet-mapping> <!-- 注册字符集过滤器,解决post请求的中文乱码问题--> <filter> <filter-name>characterEncodingFilter</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> <init-param> <param-name>forRequestEncoding</param-name> <param-value>true</param-value> </init-param> <init-param> <param-name>forResponseEncoding</param-name> <param-value>true</param-value> </init-param> </filter> <filter-mapping> <filter-name>characterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping></web-app>
1.文件上传
文件上传分为三种方式：
单个文件单字段 多个文件单字段 多个文件多字段
注意点：
1、提交方式为表单的post请求2、from属性中必须有enctype=“multipart/form-data”3、如果是单字段多文件：输入框中的属性必须为：multiple=“multiple”4、表单中的属性name必须和后端参数一致
1.前端代码
<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>文件上传</title></head><body><div> <p style="text-align: center">文件上传（单个文件单字段上传）</p> <form action="${pageContext.request.contextPath}/uploadFile1.mvc" method="post" enctype="multipart/form-data"> <input type="file" name="file"> <input type="submit" value="提交"> </form></div><div> <p style="text-align: center">文件上传（多文件单字段上传）</p> <form action="${pageContext.request.contextPath}/uploadFile2.mvc" method="post" enctype="multipart/form-data"> <input type="file" name="file" multiple="multiple"> <input type="submit" value="提交"> </form></div><div> <p style="text-align: center">文件上传（多文件多字段上传）</p> <form action="${pageContext.request.contextPath}/uploadFile2.mvc" method="post" enctype="multipart/form-data"> <input type="file" name="file" > <input type="file" name="file" > <input type="submit" value="提交"> </form></div></body></html>
2.后端代码
import org.springframework.stereotype.Controller;import org.springframework.web.bind.annotation.PostMapping;import org.springframework.web.multipart.MultipartFile;import org.springframework.web.servlet.ModelAndView;import javax.servlet.http.HttpSession;import java.io.File;import java.io.IOException;/** * @author compass * @version 1.0 * @date 2021-05-11 14:33 */@Controllerpublic class UploadIFileController { // 处理单个文件上传 @PostMapping("/uploadFile1.mvc") public ModelAndView uploadFile1(MultipartFile file, HttpSession session) throws IOException { ModelAndView view = new ModelAndView(); // 得到文件名称 String filename=file.getOriginalFilename(); System.out.println("文件名称："+filename); if (!file.isEmpty()){ // 判断文件的后缀 if (filename.endsWith(".jpg")||filename.endsWith(".png")||filename.endsWith(".txt")); //设置文件的保存路径 String savePath="C:\\Users\\14823\\IdeaProjects\\springMVC\\fileupload\\src\\main\\webapp\\WEB-INF\\file"; File srcFile = new File(savePath,filename); // 执行文件保存操作 file.transferTo(srcFile); view.setViewName("forward:/uploadSuccess.jsp"); }else { view.setViewName("forward:/uploadFailed.jsp"); } return view; } // 处理多文件上传 @PostMapping("/uploadFile2.mvc") public ModelAndView uploadFile2(MultipartFile[] file,HttpSession session) throws IOException { ModelAndView view = new ModelAndView(); //设置文件的保存路径 String savePath="C:\\Users\\14823\\IdeaProjects\\springMVC\\fileupload\\src\\main\\webapp\\WEB-INF\\file"; String[] filenames = new String[file.length]; // 只要上传过来的文件为空或者是不符合指定类型的都会上传失败 for (int i = 0; i <filenames.length ; i++) { // 判断上传过来的文件是否为空 if (!file[i].isEmpty()){ String filename=file[i].getOriginalFilename(); // 判断文件类型 if (filename.endsWith(".txt")||filename.endsWith(".jpg")||filename.endsWith(".png")){ // 创建一个文件对象 File srcFile = new File(savePath, filename); // 执行保存文件操作 file[i].transferTo(srcFile); view.setViewName("forward:/uploadSuccess.jsp"); }else { view.setViewName("forward:/uploadSuccess.jsp"); } }else { view.setViewName("forward:/uploadFailed.jsp"); } } return view; }}
2.文件下载
文件下分为两种情况：
文件名称是纯英文字母的 文件名带有中文不处理会乱码的
1.前端代码
<%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head> <title>文件下载</title></head><body><h1 style="text-align: center"><a href="${pageContext.request.contextPath}/download1.mvc?filename=preview.jpg" rel="external nofollow" >文件下载(非中文名称)</a></h1><h1 style="text-align: center"><a href="${pageContext.request.contextPath}/download2.mvc?filename=文件下载.txt" rel="external nofollow" >文件下载(中文名称)</a></h1></body></html>
2.后端代码
/** * @author compass * @version 1.0 * @date 2021-05-11 15:23 */@Controllerpublic class DownloadController { // 非中文名称文件下载 @GetMapping("/download1.mvc") public ResponseEntity <byte[]> fileDownload1(String filename,HttpServletRequest request) throws IOException { String path="C:\\Users\\14823\\IdeaProjects\\springMVC\\fileupload\\src\\main\\webapp\\WEB-INF\\file\\"; File file = new File(path,filename); HttpHeaders header = new HttpHeaders(); header.setContentDispositionFormData("attachment",filename); header.setContentType(MediaType.APPLICATION_OCTET_STREAM); ResponseEntity<byte[]> result = new ResponseEntity<>(FileUtils.readFileToByteArray(file), header, HttpStatus.OK); return result; } // 中文名称文件下载 @GetMapping("/download2.mvc") public ResponseEntity <byte[]> fileDownload2(String filename,HttpServletRequest request) throws IOException { System.out.println(filename); String path="C:\\Users\\14823\\IdeaProjects\\springMVC\\fileupload\\src\\main\\webapp\\WEB-INF\\file\\"; filename = filename.replace("_", "%"); filename= URLDecoder.decode(filename,"UTF-8"); String downloadFile=""; if (request.getHeader("USER-AGENT").toLowerCase().indexOf("msie")>0){ filename= URLEncoder.encode(filename,"UTF-8"); downloadFile=filename.replaceAll("+","%20"); }else { downloadFile=new String(filename.getBytes("UTF-8"),"ISO-8859-1"); } File file = new File(path,filename); HttpHeaders header = new HttpHeaders(); header.setContentDispositionFormData("attachment",downloadFile); header.setContentType(MediaType.APPLICATION_OCTET_STREAM); ResponseEntity<byte[]> result = new ResponseEntity<>(FileUtils.readFileToByteArray(file), header, HttpStatus.OK); return result; }}
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。
耿耿于怀着过去和忐忑不安着未来的人，也常常挥霍无度着现在。
