导入maven依赖
1 <dependencies> 2 <!--文件上传--> 3 <dependency> 4 <groupId>commons-fileupload</groupId> 5 <artifactId>commons-fileupload</artifactId> 6 <version>1.3.3</version> 7 </dependency> 8 <!--servlet-api 导入高版本--> 9 <dependency> 10 <groupId>javax.servlet</groupId> 11 <artifactId>javax.servlet-api</artifactId> 12 <version>4.0.1</version> 13 </dependency> 14 </dependencies>
配置web.xml
1 <?xml version="1.0" encoding="UTF-8"?> 2 <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" 5 version="4.0"> 6 7 <servlet> 8 <servlet-name>DispatcherServlet</servlet-name> 9 <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> 10 <init-param> 11 <param-name>contextConfigLocation</param-name> 12 <param-value>classpath:applicationContext.xml</param-value> 13 </init-param> 14 <load-on-startup>1</load-on-startup> 15 </servlet> 16 17 <servlet-mapping> 18 <servlet-name>DispatcherServlet</servlet-name> 19 <url-pattern>/</url-pattern> 20 </servlet-mapping> 21 22 23 <!--防止中文乱码--> 24 <filter> 25 <filter-name>encoding</filter-name> 26 <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class> 27 <init-param> 28 <param-name>encoding</param-name> 29 <param-value>UTF-8</param-value> 30 </init-param> 31 </filter> 32 <filter-mapping> 33 <filter-name>encoding</filter-name> 34 <url-pattern>/*</url-pattern> 35 </filter-mapping> 36 </web-app>
在src下的resources下建applicationContext.xml
1 <?xml version="1.0" encoding="UTF-8"?> 2 <beans xmlns="http://www.springframework.org/schema/beans" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:context="http://www.springframework.org/schema/context" 5 xmlns:mvc="http://www.springframework.org/schema/mvc" 6 xsi:schemaLocation="http://www.springframework.org/schema/beans 7 http://www.springframework.org/schema/beans/spring-beans.xsd 8 http://www.springframework.org/schema/context 9 http://www.springframework.org/schema/context/spring-context.xsd 10 http://www.springframework.org/schema/mvc 11 http://www.springframework.org/schema/mvc/spring-mvc.xsd"> 12 <!--自动扫描包,下面注解类交给iod容器处理--> 13 <context:component-scan base-package="com.rzk.controller"/> 14 <!--静态资源过滤--> 15 <mvc:default-servlet-handler/> 16 <!--注解驱动--> 17 <mvc:annotation-driven/> 18 <!--JSON乱码问题配置--> 19 <mvc:annotation-driven> 20 <mvc:message-converters> 21 <bean class="org.springframework.http.converter.StringHttpMessageConverter"> 22 <constructor-arg value="UTF-8"/> 23 </bean> 24 <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"> 25 <property name="objectMapper"> 26 <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean"> 27 <property name="failOnEmptyBeans" value="false"/> 28 </bean> 29 </property> 30 </bean> 31 </mvc:message-converters> 32 </mvc:annotation-driven> 33 34 35 <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> 36 <property name="prefix" value="/WEB-INF/jsp/"/> 37 <property name="suffix" value=".jsp"/> 38 </bean> 39 40 <!--文件上传配置--> 41 <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> 42 <!-- 请求的编码格式，必须和jSP的pageEncoding属性一致，以便正确读取表单的内容，默认为ISO-8859-1 --> 43 <property name="defaultEncoding" value="utf-8"/> 44 <!-- 上传文件大小上限，单位为字节（10485760=10M） --> 45 <property name="maxUploadSize" value="10485760"/> 46 <property name="maxInMemorySize" value="40960"/> 47 </bean> 48 49 </beans>
新建上传页面
1 <form action="${pageContext.request.contextPath}/file/upload" method="post" enctype="multipart/form-data"> 2 <input type="file" name="file"> 3 <input type="submit" value="upload"> 4 </form>
controller
1 @Controller 2 @RequestMapping("/file") 3 public class FileController { 4 //@RequestParam("file") 将name=file控件得到的文件封装成CommonsMultipartFile 对象 5 //批量上传CommonsMultipartFile则为数组即可 6 @RequestMapping("/upload") 7 public String fileUpload(@RequestParam("file") CommonsMultipartFile file , HttpServletRequest request) throws IOException { 8 9 //获取文件名 : file.getOriginalFilename(); 10 String uploadFileName = file.getOriginalFilename(); 11 12 //如果文件名为空，直接回到首页！ 13 if ("".equals(uploadFileName)){ 14 return "redirect:/index.jsp"; 15 } 16 System.out.println("上传文件名 : "+uploadFileName); 17 18 //上传路径保存设置 19 String path = request.getServletContext().getRealPath("/upload"); 20 //如果路径不存在，创建一个 21 File realPath = new File(path); 22 if (!realPath.exists()){ 23 realPath.mkdir(); 24 } 25 System.out.println("上传文件保存地址："+realPath); 26 27 InputStream is = file.getInputStream(); //文件输入流 28 OutputStream os = new FileOutputStream(new File(realPath,uploadFileName)); //文件输出流 29 30 //读取写出 31 int len=0; 32 byte[] buffer = new byte[1024]; 33 while ((len=is.read(buffer))!=-1){ 34 os.write(buffer,0,len); 35 os.flush(); 36 } 37 os.close(); 38 is.close(); 39 return "redirect:/index.jsp"; 40 } 41 }
controller第二种上传方式
1 @RequestMapping("/upload2") 2 public String fileUpload2(@RequestParam("file") CommonsMultipartFile file, HttpServletRequest request) throws IOException { 3 4 //上传路径保存设置 5 String path = request.getServletContext().getRealPath("/upload"); 6 File realPath = new File(path); 7 if (!realPath.exists()){ 8 realPath.mkdir(); 9 } 10 //上传文件地址 11 System.out.println("上传文件保存地址："+realPath); 12 13 //通过CommonsMultipartFile的方法直接写文件（注意这个时候） 14 file.transferTo(new File(realPath +"/"+ file.getOriginalFilename())); 15 16 return "redirect:/index.jsp"; 17 }
下载文件
1 @RequestMapping(value="/download") 2 public String downloads(HttpServletResponse response , HttpServletRequest request) throws Exception{ 3 //要下载的图片地址 4 String path = request.getServletContext().getRealPath("/upload"); 5 String fileName = "1.jpg"; 6 7 //1、设置response 响应头 8 response.reset(); //设置页面不缓存,清空buffer 9 response.setCharacterEncoding("UTF-8"); //字符编码 10 response.setContentType("multipart/form-data"); //二进制传输数据 11 //设置响应头 12 response.setHeader("Content-Disposition", 13 "attachment;fileName="+ URLEncoder.encode(fileName, "UTF-8")); 14 15 File file = new File(path,fileName); 16 //2、 读取文件--输入流 17 InputStream input=new FileInputStream(file); 18 //3、 写出文件--输出流 19 OutputStream out = response.getOutputStream(); 20 21 byte[] buff =new byte[1024]; 22 int index=0; 23 //4、执行 写出操作 24 while((index= input.read(buff))!= -1){ 25 out.write(buff, 0, index); 26 out.flush(); 27 } 28 out.close(); 29 input.close(); 30 return "ok"; 31 }
链接
1 <a href="/file/download">下载</a>
下载图片只需要改一下第5行代码就可以了