基于Spring MVC实现文件上传：
-
使用commons-fileupload实现上传文件到本地目录。
-
实现上传文件到阿里云OSS和从阿里云OSS下载文件到本地。
1. 创建项目
选择Maven快速构建web项目，项目名称为case14-springmvc03。
2. 配置Maven依赖
<?xml version="1.0" encoding="UTF-8"?>
<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/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.wfit.springmvc</groupId>
<artifactId>springmvc02</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.8</maven.compiler.source>
<maven.compiler.target>1.8</maven.compiler.target>
</properties>
<dependencies>
<!--spring mvc-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.3.8</version>
</dependency>
<!--servlet-->
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.1.0</version>
<scope>provided</scope>
</dependency>
<!--fileupload-->
<dependency>
<groupId>commons-fileupload</groupId>
<artifactId>commons-fileupload</artifactId>
<version>1.4</version>
</dependency>
<!--aliyun-sdk-oss-->
<dependency>
<groupId>com.aliyun.oss</groupId>
<artifactId>aliyun-sdk-oss</artifactId>
<version>3.15.1</version>
</dependency>
</dependencies>
</project>3. 创建Spring MVC配置文件
src.main.resources目录下创建spring-mvc.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: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">
<!--开启注解-->
<context:component-scan base-package="com.wfit"/>
<!--启用mvc-->
<mvc:annotation-driven></mvc:annotation-driven>
<!--文件上传解析器-->
<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
<!--设置上传大小 最大1M-->
<property name="maxUploadSize" value="1048576"/>
</bean>
</beans>4. 配置web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<!--解决POST中文乱码问题 过滤器-->
<filter>
<filter-name>encodingFilter</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>
</filter>
<filter-mapping>
<filter-name>encodingFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
<!--配置前端控制器DispatcherServlet-->
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!--加载SpringMVC文件-->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:spring-mvc.xml</param-value>
</init-param>
<!--启动容器时加载servlet-->
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<!--表示拦截所有请求-->
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>5. 创建UploadController类
在src.main.java.com.wfit.upload目录下创建UploadController类，实现文件上传。
@Controller
@RequestMapping("/upload")
public class UploadController {
/**
* 文件上传
* @param file
* @return
*/
@PostMapping("/upload")
@ResponseBody
public String upload(MultipartFile file) throws IOException {
//验证文件是否为空
if(ObjectUtils.isEmpty(file) || file.getSize() <=0){
return "file is empty";
}
//创建上传文件位置
File uploadDir = new File("D:\\upload");
//获取文件名
String fileName = file.getOriginalFilename();
//创建目标文件
File desFile = new File(uploadDir,fileName);
//执行上传操作
file.transferTo(desFile);
return "success";
}
}6. 创建OssController类
在src.main.java.com.wfit.upload目录下创建OssController类，实现上传文件到阿里云OSS和从阿里云OSS下载文件到本地。
@Controller
@RequestMapping("/oss")
public class OssController {
//访问OSS的域名
private static String endpoint = "oss-cn-beijing.aliyuncs.com";
//accessKeyId和accessKeySecret是OSS的访问密钥
private static String accessKeyId = "<yourAccessKeyId>";
private static String accessKeySecret = "<yourAccessKeySecret>";
//Bucket用来管理所存储Object的存储空间
private static String bucketName = "<yourBucketName>";
//目标文件
private static String objectName = "upload/123.txt";
/**
* 上传文件到阿里云OSS
* @return
*/
@PostMapping("/upload")
@ResponseBody
public String upload(MultipartFile file) throws IOException {
//验证文件是否为空
if(ObjectUtils.isEmpty(file) || file.getSize() <=0){
return "file is empty";
}
InputStream inputStream = file.getInputStream();
// 创建OSSClient实例
OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);
try {
// 创建PutObjectRequest对象
PutObjectRequest putObjectRequest = new PutObjectRequest(bucketName, objectName, inputStream);
// 设置该属性可以返回response。如果不设置，则返回的response为空
putObjectRequest.setProcess("true");
// 创建PutObject请求
PutObjectResult result = ossClient.putObject(putObjectRequest);
// 如果上传成功，则返回200
System.out.println(result.getResponse().getStatusCode());
} catch (Exception e) {
System.out.println("Error Message:" + e.getMessage());
}
return "success";
}
/**
* 下载阿里云文件到本地
* @return
*/
@PostMapping("/download")
@ResponseBody
public String download(String objName,String path) throws IOException {
//下载目录
String pathName = "download/123.txt";
// 创建OSSClient实例
OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);
try {
// 下载Object到本地文件，并保存到指定的本地路径中
ossClient.getObject(new GetObjectRequest(bucketName, objectName), new File(pathName));
} catch (Exception e) {
System.out.println("Error Message:" + e.getMessage());
}
return "success";
}
}7. Postman执行上传文件到本地目录
8. Postman执行上传到阿里云OSS
9. Postman执行从阿里云OSS下载文件到本地
