SpringMVC框架实现图片上传与下载

<dependencies>   <!-- 用于生成图片的缩略图 --> <dependency>  <groupId>net.coobird</groupId>  <artifactId>thumbnailator</artifactId>  <version>0.4.8</version> </dependency>    <!-- 单元测试包 -->  <dependency>   <groupId>junit</groupId>   <artifactId>junit</artifactId>   <version>3.8.1</version>   <scope>test</scope>  </dependency>   <!-- springmvc夹包 -->  <dependency>  <groupId>org.springframework</groupId>  <artifactId>spring-webmvc</artifactId>  <version>4.3.11.RELEASE</version> </dependency>  <!-- spring核心包，用于依赖注入 --> <dependency>  <groupId>org.springframework</groupId>  <artifactId>spring-core</artifactId>  <version>4.3.11.RELEASE</version> </dependency>  <!-- servlet夹包 --> <dependency>  <groupId>javax.servlet</groupId>  <artifactId>javax.servlet-api</artifactId>  <version>3.1.0</version>   </dependency>  <!-- javaee包，在jsp文件中使用--> <dependency>  <groupId>javax</groupId>  <artifactId>javaee-api</artifactId>  <version>7.0</version>   </dependency>  <!-- 文件上传的夹包 ，用于文件上传-->  <dependency>  <groupId>commons-fileupload</groupId>  <artifactId>commons-fileupload</artifactId>  <version>1.3.1</version> </dependency>  <!-- jstl标签包，在jsp中使用 --> <dependency>  <groupId>javax.servlet</groupId>  <artifactId>jstl</artifactId>  <version>1.2</version> </dependency>  </dependencies>

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xmlns="http://java.sun.com/xml/ns/javaee"    xsi:schemaLocation="   http://java.sun.com/xml/ns/javaee    http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5">    <!-- 配置springmvc的前端控制器，可以配置多个前端控制器来拦截不同的url -->   <servlet>  <servlet-name>spring</servlet-name>  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>  <init-param>   <param-name>contextConfigLocation</param-name>   <param-value>classpath:springmvc.xml</param-value>  </init-param>  <load-on-startup>1</load-on-startup> </servlet> <servlet-mapping>  <servlet-name>spring</servlet-name>  <url-pattern>/</url-pattern> </servlet-mapping>  </web-app>

<?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/mvc    http://www.springframework.org/schema/mvc/spring-mvc-3.2.xsd http://www.springframework.org/schema/beans  http://www.springframework.org/schema/beans/spring-beans-3.2.xsd http://www.springframework.org/schema/context  http://www.springframework.org/schema/context/spring-context-3.2.xsd">  <!-- 配置jsp的视图解析器，可以配置多个viewresolver--> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!-- 会用到EL表达式以及jstl的标签，必须包含这个类 -->    <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"></property>  <property name="prefix" value="/" />  <property name="suffix" value=".jsp" /> </bean>  <!-- 1、自动注册defaultAnnotationHandlermapping ，AnnotationMethodhandlerAdapter，可以根据URL映射到方法--> <!-- 2、数据绑定，数字和日期的format，如@NumberFormat ,@DateFormat,还有xml和json的默认读写功能 -->   <mvc:annotation-driven />       <!-- 1.加入对静态资源的处理 -->   <!-- 2.允许使用“/”做整体映射 -->   <mvc:default-servlet-handler/>    <!-- 自动扫描相关的包 --> <context:component-scan base-package="thumbnail"/>   <!-- 对文件上传的处理，这里声明的id必须为multipartResolver--> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" >    <!-- 最大为100M，单位为字节 -->  <property name="maxUploadSize" value="104857600"></property>    <property name="defaultEncoding" value="utf-8"></property>    <property name="maxInMemorySize" value="40960"></property> </bean>   </beans>

@Controller@RequestMapping("/")public class ImageController {  //使用Autowired时，该业务类需要声明为@service，此时xml中不用其它的配置 @Autowired   private Upload upload;  @Autowired  private Thumbnail thumbnail;  //文件上传并生成缩略图 @RequestMapping(value="/thumb",method=RequestMethod.POST) public String GenerateImage(@RequestParam("image")CommonsMultipartFile file,HttpServletRequest request) throws IOException {  //根据相对路径获取绝对路径，图片上传后位于元数据中 String realUploadPath=request.getServletContext().getRealPath("/")+"images";   //获取上传后原图的相对地址 String imageUrl=upload.uploadImage(file, realUploadPath);  //获取生成的缩略图的相对地址 String thumbImageUrl=thumbnail.generateThumbnail(file, realUploadPath);  return "redirect:/images"; }   //显示所有图片 @RequestMapping(value="/images",method=RequestMethod.GET) public ModelAndView showImages(HttpServletRequest request,HttpServletResponse response) { //根据相对路径获取绝对路径，图片上传后位于元数据中 List<String> rawImagesList=new ArrayList<String>();  String realUploadPath=request.getServletContext().getRealPath("/")+"images";  rawImagesList=ImageList.printFile(realUploadPath+"/rawImages");  ModelAndView mv=new ModelAndView(); mv.addObject("imageList", rawImagesList); mv.setViewName("images"); return mv; }  //文件下载 @RequestMapping("/download") public void download(HttpServletRequest request,HttpServletResponse response) throws IOException { String path=request.getServletContext().getRealPath("/")+"/images/rawImages/"; String fileName=request.getParameter("filename"); File file=new File(path+fileName); if(file.exists()){ //设置MIME类型 response.setContentType("application/octet-stream");  //或者为response.setContentType("application/x-msdownload");  //设置头信息,设置文件下载时的默认文件名，同时解决中文名乱码问题 response.addHeader("Content-disposition", "attachment;filename="+new String(fileName.getBytes(), "ISO-8859-1"));  InputStream inputStream=new FileInputStream(file); ServletOutputStream outputStream=response.getOutputStream(); byte[] bs=new byte[1024]; while((inputStream.read(bs)>0)){ outputStream.write(bs); } outputStream.close(); inputStream.close();  } }}

@Servicepublic class Upload {  /* * 上传图片并返回图片的相对地址 */  public String uploadImage(CommonsMultipartFile file,String realUploadPath) throws IOException { //如果目录不存在则创建目录 File uploadFile=new File(realUploadPath+"/rawImages"); if(!uploadFile.exists()){ uploadFile.mkdirs(); }   //创建输入流 InputStream inputStream=file.getInputStream(); //生成输出地址URL String outputPath=realUploadPath+"/rawImages/"+file.getOriginalFilename(); //创建输出流 OutputStream outputStream=new FileOutputStream(outputPath);  //设置缓冲区 byte[] buffer=new byte[1024];  //输入流读入缓冲区，输出流从缓冲区写出 while((inputStream.read(buffer))>0) { outputStream.write(buffer); } outputStream.close();  //返回原图上传后的相对地址 return "images/rawImages/"+file.getOriginalFilename(); } }

@Servicepublic class Thumbnail {  //设置缩略图的宽度和高度 public static final int witdth=100; public static final int heigth=100;  /*  * 生成缩略图并且返回相对地址 */ public String generateThumbnail(CommonsMultipartFile file,String realUploadPath) throws IOException {  //如果目录不存在则创建目录 File uploadFile=new File(realUploadPath+"/thumbImages"); if(!uploadFile.exists()){ uploadFile.mkdirs(); }   //缩略图保存的绝对地址 String des=realUploadPath+"/thumbImages/"+file.getOriginalFilename(); //生成缩略图 Thumbnails.of(file.getInputStream()).size(witdth, heigth).toFile(des); //返回缩略图的相对地址 return "images/thumbImages/"+file.getOriginalFilename(); } }

public class ImageList {  //获取文件夹下所有文件名 public static List<String> printFile(String path) { File file = new File(path); List<String> images = new ArrayList<String>();  // 是文件夹的话 if (file.isDirectory()) { String[] filelist = file.list(); for (int i = 0; i < filelist.length; i++) { File readfile = new File(path + "/" + filelist[i]); if (!readfile.isDirectory()) {  images.add(readfile.getName()); } }  } return images; } }

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%><%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><title>上传图片</title></head><body><script type="text/javascript"> function validate() { var a=document.getElementById("file"); var form=document.getElementById("upload"); if(a.value==""){    alert("请先选择图片");   return false; } else{ form.submit(); }  } </script><h1 align="center">图片上传与下载</h1><p> <c:forEach var="image" items="${imageList}">   <a href="images/rawImages/${image}" rel="external nofollow" target="_blank"><img src="images/thumbImages/${image}" /></a>  <a href="${pageContext.request.contextPath}/download?filename=${image}" rel="external nofollow" >${image}</a>   </c:forEach> </p> <form id="upload" action="${pageContext.request.contextPath}/thumb" method="post" enctype="multipart/form-data"> <input id="file" type="file" name="image" id="image" >  <input type="button" value="上传" οnclick="validate()"></form> </body></html>