使用springMVC实现文件上传和下载之环境配置与上传

最近的项目中用到了文件的上传和下载功能，任务分配给了其他的同时完成。如今项目结束告一段落，我觉着这个功能比较重要，因此特意把它提取出来自己进行了尝试。

一、 基础配置：

maven导包及配置pom.xml，导包时除开springmvc的基础依赖外，需要导入文件上传下载时用到的commons-io.jsr和commons-fileupload.jar：

[html] view plain copy

1. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
2.   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">  
3.   <modelVersion>4.0.0</modelVersion>  
4.   <groupId>filLoadTest</groupId>  
5.   <artifactId>filLoadTest</artifactId>  
6.   <packaging>war</packaging>  
7.   <version>0.0.1-SNAPSHOT</version>  
8.   <name>filLoadTest Maven Webapp</name>  
9.   <url>http://maven.apache.org</url>  
10.    <build>  
11.     <finalName>filLoadTest</finalName>  
12.      <plugins>    
13.             <!-- 以下配置可以保证每次强制更新时jre版本不会变化，那我的eclipse4.4.1，maven3.2.5为例，如果不设置这个，每次强制更新时jre就会变回1.5 -->    
14.             <plugin>    
15.                 <artifactId>maven-compiler-plugin</artifactId>    
16.                 <version>2.3.2</version>    
17.                 <configuration>    
18.                     <source>1.7</source>    
19.                     <target>1.7</target>    
20.                     <encoding>UTF-8</encoding>    
21.                     <compilerArguments>    
22.                         <verbose />    
23.                         <bootclasspath>${java.home}\lib\rt.jar</bootclasspath>    
24.                     </compilerArguments>    
25.                 </configuration>    
26.             </plugin>    
27.         </plugins>    
28.   </build>  
29.   <dependencies>  
30.     <dependency>  
31.       <groupId>junit</groupId>  
32.       <artifactId>junit</artifactId>  
33.       <version>3.8.1</version>  
34.       <scope>test</scope>  
35.     </dependency>  
36.     <dependency>  
37.         <groupId>org.springframework</groupId>  
38.         <artifactId>spring-webmvc</artifactId>  
39.         <version>4.0.6.RELEASE</version>  
40.     </dependency>  
41.     <dependency>  
42.         <groupId>com.fasterxml.jackson.core</groupId>  
43.         <artifactId>jackson-annotations</artifactId>  
44.         <version>2.2.3</version>  
45.     </dependency>  
46.     <dependency>  
47.         <groupId>com.fasterxml.jackson.core</groupId>  
48.         <artifactId>jackson-core</artifactId>  
49.         <version>2.2.3</version>  
50.     </dependency>  
51.     <dependency>  
52.         <groupId>com.fasterxml.jackson.core</groupId>  
53.         <artifactId>jackson-databind</artifactId>  
54.         <version>2.2.3</version>  
55.     </dependency>  
56.     <dependency>  
57.         <groupId>commons-fileupload</groupId>  
58.         <artifactId>commons-fileupload</artifactId>  
59.         <version>1.3.1</version>  
60.     </dependency>  
61.     <dependency>  
62.         <groupId>commons-io</groupId>  
63.         <artifactId>commons-io</artifactId>  
64.         <version>2.4</version>  
65.     </dependency>  
66.   </dependencies>  
67. </project>  

web.xml基础配置：

[html] view plain copy

1. <?xml version="1.0" encoding="UTF-8"?>  
2. <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
3.     xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"  
4.     xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"  
5.     id="WebApp_ID" version="2.5">      
6.     <filter>  
7.         <description>字符集过滤器</description>  
8.         <filter-name>encodingFilter</filter-name>  
9.         <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>  
10.         <init-param>  
11.             <description>字符集编码</description>  
12.             <param-name>encoding</param-name>  
13.             <param-value>UTF-8</param-value>  
14.         </init-param>  
15.     </filter>  
16.     <filter-mapping>  
17.         <filter-name>encodingFilter</filter-name>  
18.         <url-pattern>/*</url-pattern>  
19.     </filter-mapping>  
20.     <servlet>    
21.         <servlet-name>springMVC</servlet-name>    
22.         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>    
23.         <init-param>    
24.             <param-name>contextConfigLocation</param-name>    
25.             <param-value>classpath:spring.xml</param-value>    
26.         </init-param>      
27.     </servlet>    
28.     <servlet-mapping>    
29.         <servlet-name>springMVC</servlet-name>    
30.         <url-pattern>*.do</url-pattern>    
31.     </servlet-mapping>  
32.     <welcome-file-list>  
33.         <welcome-file>index.html</welcome-file>  
34.         <welcome-file>index.htm</welcome-file>  
35.         <welcome-file>index.jsp</welcome-file>  
36.         <welcome-file>default.html</welcome-file>  
37.         <welcome-file>default.htm</welcome-file>  
38.         <welcome-file>default.jsp</welcome-file>  
39.     </welcome-file-list>    
40. </web-app>    

spring基础配置spring.xml:

[html] view plain copy

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" xmlns:p="http://www.springframework.org/schema/p"    
4.     xmlns:context="http://www.springframework.org/schema/context"    
5.     xmlns:mvc="http://www.springframework.org/schema/mvc"      
6.     xsi:schemaLocation="    
7.         http://www.springframework.org/schema/beans     
8.         http://www.springframework.org/schema/beans/spring-beans-3.0.xsd    
9.         http://www.springframework.org/schema/context     
10.         http://www.springframework.org/schema/context/spring-context-3.0.xsd  
11.         http://www.springframework.org/schema/mvc   
12.         http://www.springframework.org/schema/mvc/spring-mvc.xsd">    
13.   
14.   
15.     <context:annotation-config />    
16.     <mvc:annotation-driven />  
17.     <context:component-scan base-package="controllers" />    
18.       
19.     <!-- 避免IE执行AJAX时,返回JSON出现下载文件 -->  
20.     <bean id="mappingJacksonHttpMessageConverter"  
21.         class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">  
22.         <property name="supportedMediaTypes">  
23.             <list>  
24.                 <value>text/html;charset=utf-8</value>  
25.             </list>  
26.         </property>  
27.     </bean>  
28.   
29.   
30.     <!-- 启动Spring MVC的注解功能，完成请求和注解POJO的映射 -->  
31.     <bean  
32.         class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">  
33.         <property name="messageConverters">  
34.             <list>  
35.                 <ref bean="mappingJacksonHttpMessageConverter" /><!-- json转换器 -->  
36.             </list>  
37.         </property>  
38.     </bean>  
39.       
40.     <!-- 支持上传文件 -->  
41.     <bean id="multipartResolver"  
42.         class="org.springframework.web.multipart.commons.CommonsMultipartResolver" >  
43.         <!-- 100M -->  
44.         <property name="maxUploadSize" value="104857600"></property>      
45.         <property name="defaultEncoding" value="utf-8"></property>     
46.     </bean>  
47. </beans>    

二、文件上传的代码

上传的简单页面index.html,要注意form表单提交时的entype的设置：

[html] view plain copy

1. <!DOCTYPE html>  
2. <html>  
3. <head>  
4.   <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />  
5. </head>  
6. <body>  
7.    <form action="./upLoadFile.do" method="post" enctype="multipart/form-data">  
8.                  选择文件：<input type="file" name="file"/>  
9.                  <input type="submit" value="提交"/>  
10.    </form>  
11. </body>  
12. </html>  

上传对应的后台java代码，具体问题见注释：

[java] view plain copy

1. package controllers;  
2.   
3.   
4. import java.io.File;  
5. import java.io.IOException;  
6. import java.util.Iterator;  
7. import javax.servlet.http.HttpServletRequest;  
8. import org.apache.commons.io.FileUtils;  
9. import org.springframework.http.HttpHeaders;  
10. import org.springframework.http.HttpStatus;  
11. import org.springframework.http.MediaType;  
12. import org.springframework.http.ResponseEntity;  
13. import org.springframework.stereotype.Controller;  
14. import org.springframework.web.bind.annotation.RequestMapping;  
15. import org.springframework.web.bind.annotation.RequestMethod;  
16. import org.springframework.web.bind.annotation.RequestParam;  
17. import org.springframework.web.multipart.MultipartFile;  
18. import org.springframework.web.multipart.MultipartHttpServletRequest;  
19. import org.springframework.web.multipart.commons.CommonsMultipartResolver;  
20.   
21.   
22. @Controller  
23. public class fileController {  
24.   
25.   
26.     /** 
27.      * 文件上传 
28.      *  
29.      * @author：tuzongxun 
30.      * @Title: upLoadFile 
31.      * @param @param file 
32.      * @param @param request 
33.      * @param @throws IllegalStateException 
34.      * @param @throws IOException 
35.      * @return void 
36.      * @date Apr 28, 2016 1:22:00 PM 
37.      * @throws 
38.      */  
39.     @RequestMapping(value = "/upLoadFile.do", method = RequestMethod.POST)  
40.     public void upLoadFile(HttpServletRequest request)  
41.             throws IllegalStateException, IOException {  
42.         // @RequestParam("file") MultipartFile file,  
43.         CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(  
44.                 request.getSession().getServletContext());  
45.         // 判断 request 是否有文件上传,即多部分请求  
46.         if (multipartResolver.isMultipart(request)) {  
47.             // 转换成多部分request  
48.             MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest) request;  
49.             // 取得request中的所有文件名  
50.             Iterator<String> iter = multiRequest.getFileNames();  
51.             while (iter.hasNext()) {  
52.                 // 取得上传文件  
53.                 MultipartFile f = multiRequest.getFile(iter.next());  
54.                 if (f != null) {  
55.                     // 取得当前上传文件的文件名称  
56.                     String myFileName = f.getOriginalFilename();  
57.                     // 如果名称不为“”,说明该文件存在，否则说明该文件不存在  
58.                     if (myFileName.trim() != "") {  
59.                         // 定义上传路径  
60.                         String path = "C:\\Users\\tuzongxun123\\Desktop\\"  
61.                                 + myFileName;  
62.                         File localFile = new File(path);  
63.                         f.transferTo(localFile);  
64.                     }  
65.                 }  
66.             }  
67.         }  
68.     }  
69. }  

页面效果图如下，当选择文件提交后，便会看到选中的文件被传到了代码中指定的位置，这里是我的桌面上。