springMVC配置环境实现文件上传和下载

最近的项目中用到了文件的上传和下载功能，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。

下面就是springMVC配置环境实现文件上传和下载的具体步骤，供大家参考，具体内容如下

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：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>filLoadTest</groupId>
 <artifactId>filLoadTest</artifactId>
 <packaging>war</packaging>
 <version>0.0.1-SNAPSHOT</version>
 <name>filLoadTest Maven Webapp</name>
 <url>http://maven.apache.org</url>
 <build>
 <finalName>filLoadTest</finalName>
 <plugins>
  <!-- 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 -->
  <plugin>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>2.3.2</version>
  <configuration>
   <source>1.7</source>
   <target>1.7</target>
   <encoding>UTF-8</encoding>
   <compilerArguments>
   <verbose />
   <bootclasspath>${java.home}\lib\rt.jar</bootclasspath>
   </compilerArguments>
  </configuration>
  </plugin>
 </plugins>
 </build>
 <dependencies>
 <dependency>
 <groupId>junit</groupId>
 <artifactId>junit</artifactId>
 <version>3.8.1</version>
 <scope>test</scope>
 </dependency>
 <dependency>
 <groupId>org.springframework</groupId>
 <artifactId>spring-webmvc</artifactId>
 <version>4.0.6.RELEASE</version>
 </dependency>
 <dependency>
 <groupId>com.fasterxml.jackson.core</groupId>
 <artifactId>jackson-annotations</artifactId>
 <version>2.2.3</version>
 </dependency>
 <dependency>
 <groupId>com.fasterxml.jackson.core</groupId>
 <artifactId>jackson-core</artifactId>
 <version>2.2.3</version>
 </dependency>
 <dependency>
 <groupId>com.fasterxml.jackson.core</groupId>
 <artifactId>jackson-databind</artifactId>
 <version>2.2.3</version>
 </dependency>
 <dependency>
 <groupId>commons-fileupload</groupId>
 <artifactId>commons-fileupload</artifactId>
 <version>1.3.1</version>
 </dependency>
 <dependency>
 <groupId>commons-io</groupId>
 <artifactId>commons-io</artifactId>
 <version>2.4</version>
 </dependency>
 </dependencies>
</project>

web.xml基础配置：

<?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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
 id="WebApp_ID" version="2.5">
 <filter>
 <description>字符集过滤器</description>
 <filter-name>encodingFilter</filter-name>
 <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
 <init-param>
  <description>字符集编码</description>
  <param-name>encoding</param-name>
  <param-value>UTF-8</param-value>
 </init-param>
 </filter>
 <filter-mapping>
 <filter-name>encodingFilter</filter-name>
 <url-pattern>/*</url-pattern>
 </filter-mapping>
 <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:spring.xml</param-value>
 </init-param>
 </servlet>
 <servlet-mapping>
 <servlet-name>springMVC</servlet-name>
 <url-pattern>*.do</url-pattern>
 </servlet-mapping>
 <welcome-file-list>
 <welcome-file>index.html</welcome-file>
 <welcome-file>index.htm</welcome-file>
 <welcome-file>index.jsp</welcome-file>
 <welcome-file>default.html</welcome-file>
 <welcome-file>default.htm</welcome-file>
 <welcome-file>default.jsp</welcome-file>
 </welcome-file-list>
</web-app>

spring基础配置spring.xml:

<?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:p="http://www.springframework.org/schema/p"
 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-3.0.xsd
 http://www.springframework.org/schema/context
 http://www.springframework.org/schema/context/spring-context-3.0.xsd
 http://www.springframework.org/schema/mvc
 http://www.springframework.org/schema/mvc/spring-mvc.xsd">


 <context:annotation-config />
 <mvc:annotation-driven />
 <context:component-scan base-package="controllers" />

 <!-- 避免IE执行AJAX时,返回JSON出现下载文件 -->
 <bean id="mappingJacksonHttpMessageConverter"
 class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
 <property name="supportedMediaTypes">
  <list>
  <value>text/html;charset=utf-8</value>
  </list>
 </property>
 </bean>


 <!-- 启动Spring MVC的注解功能，完成请求和注解POJO的映射 -->
 <bean
 class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter">
 <property name="messageConverters">
  <list>
  <ref bean="mappingJacksonHttpMessageConverter" /><!-- json转换器 -->
  </list>
 </property>
 </bean>

 <!-- 支持上传文件 -->
 <bean id="multipartResolver"
 class="org.springframework.web.multipart.commons.CommonsMultipartResolver" >
 <!-- 100M -->
 <property name="maxUploadSize" value="104857600"></property>
 <property name="defaultEncoding" value="utf-8"></property>
 </bean>
</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：

<!DOCTYPE html>
<html>
<head>
 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
</head>
<body>
 <form action="./upLoadFile.do" method="post" enctype="multipart/form-data">
   选择文件：<input type="file" name="file"/>
   <input type="submit" value="提交"/>
 </form>
</body>
</html>

上传对应的后台java代码，具体问题见注释：

package controllers;


import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import javax.servlet.http.HttpServletRequest;
import org.apache.commons.io.FileUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.MultipartHttpServletRequest;
import org.springframework.web.multipart.commons.CommonsMultipartResolver;


@Controller
public class fileController {


 /**
 * 文件上传
 *
 * @author：tuzongxun
 * @Title: upLoadFile
 * @param @param file
 * @param @param request
 * @param @throws IllegalStateException
 * @param @throws IOException
 * @return void
 * @date Apr 28, 2016 1:22:00 PM
 * @throws
 */
 @RequestMapping(value = "/upLoadFile.do", method = RequestMethod.POST)
 public void upLoadFile(HttpServletRequest request)
  throws IllegalStateException, IOException {
 // @RequestParam("file") MultipartFile file,
 CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(
  request.getSession().getServletContext());
 // 判断 request 是否有文件上传,即多部分请求
 if (multipartResolver.isMultipart(request)) {
  // 转换成多部分request
  MultipartHttpServletRequest multiRequest = (MultipartHttpServletRequest) request;
  // 取得request中的所有文件名
  Iterator<String> iter = multiRequest.getFileNames();
  while (iter.hasNext()) {
  // 取得上传文件
  MultipartFile f = multiRequest.getFile(iter.next());
  if (f != null) {
   // 取得当前上传文件的文件名称
   String myFileName = f.getOriginalFilename();
   // 如果名称不为“”,说明该文件存在，否则说明该文件不存在
   if (myFileName.trim() != "") {
   // 定义上传路径
   String path = "C:\\Users\\tuzongxun123\\Desktop\\"
    + myFileName;
   File localFile = new File(path);
   f.transferTo(localFile);
   }
  }
  }
 }
 }
}

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，页面效果图如下

三、文件下载

文件下载需要获取下载文件的存储路径，这里只是手动填入，如果是在具体项目中，可以把文件名和上传后的存储路径保存在数据库中。然后增加一个文件列表的页面展示文件名和文件路径，然后点击下载的时候把相应的文件名和路径传到后台操作。

/**
  * 文件下载，需要文件名和文件地址
  *
  * @author：tuzongxun
  * @Title: download
  * @param@param name
  * @param@param path
  * @param@return
  * @param@throws IOException
  * @returnResponseEntity<byte[]>
  * @date Apr 28,2016 1:21:32 PM
  * @throws
  */
 @RequestMapping(value = "/downLoadFile.do")
 public ResponseEntity<byte[]> download(@RequestParam("name") String name,
   @RequestParam("filePath") String path) throws IOException {
  File file = new File(path);
  HttpHeaders headers = new HttpHeaders();
  String fileName = new String(name.getBytes("UTF-8"), "iso-8859-1");// 为了解决中文名称乱码问题
  headers.setContentDispositionFormData("attachment", fileName);
  headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
  return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),
    headers, HttpStatus.CREATED);
 }

Html页面，这里只是简单的填写文件名和文件路径，用form表单提交到后台，然后后台会控制response在页面弹出保存文件路径的选择框，当然了，这里的后台我没有做什么处理，如果文件不存在是会报错的，可以进行相应的处理：
文件下载：  

</br> </br>
<form action="./downLoadFile.do"style="border:1px solid grey;width:auto;" method="post">
  文件名：<input type="text" name="name"/></br></br>
  文件路径：<input type="text" name="filePath"/></br></br>
  <input type="submit" value="确认下载"/>
</form>

页面视图如下：

如果文件不存在，报错如下：

以上就是本文的全部内容，希望对大家的学习有所帮助。