JAVA实现文件上传至阿里云
注册阿里云账号后,开通好对象存储服务（OSS），三个月试用
阿里云登录页 (aliyun.com)
目录
一.创建Bucket
二.获取AccessKey（密钥）
三.参考官方SDK文件，编写入门程序
1.复制阿里云OSS依赖，粘贴到pom.xml文件里
2. 将上传文件流的Demo测试类复制到test文件里
四.集成OSS（运用于项目中）
1. 在yml文件配置自定义阿里云OSS信息
2.编写阿里云工具类（官方代码改编）
3.编写文件上传类（接口）
一.创建Bucket
二.获取AccessKey（密钥）
注意：保存好你的AccessKey ID！！
三.参考官方SDK文件，编写入门程序
1.复制阿里云OSS依赖，粘贴到pom.xml文件里
<!--阿里云OSS--><dependency><groupId>com.aliyun.oss</groupId><artifactId>aliyun-sdk-oss</artifactId><version>3.15.1</version></dependency>
2. 将上传文件流的Demo测试类复制到test文件里
import com.aliyun.oss.ClientException;
import com.aliyun.oss.OSS;
import com.aliyun.oss.common.auth.*;
import com.aliyun.oss.OSSClientBuilder;
import com.aliyun.oss.OSSException;
import com.aliyun.oss.model.PutObjectRequest;
import com.aliyun.oss.model.PutObjectResult;
import java.io.FileInputStream;
import java.io.InputStream;public class Demo {public static void main(String[] args) throws Exception {// Endpoint以华东1（杭州）为例，其它Region请按实际情况填写。String endpoint = "https://oss-cn-hangzhou.aliyuncs.com";// 从环境变量中获取访问凭证。运行本代码示例之前，请确保已设置环境变量OSS_ACCESS_KEY_ID和OSS_ACCESS_KEY_SECRET。EnvironmentVariableCredentialsProvider credentialsProvider = CredentialsProviderFactory.newEnvironmentVariableCredentialsProvider();// 填写Bucket名称，例如examplebucket。String bucketName = "examplebucket";// 填写Object完整路径，完整路径中不能包含Bucket名称，例如exampledir/exampleobject.txt。String objectName = "exampledir/exampleobject.txt";// 填写本地文件的完整路径，例如D:\\localpath\\examplefile.txt。// 如果未指定本地路径，则默认从示例程序所属项目对应本地路径中上传文件流。String filePath= "D:\\localpath\\examplefile.txt";// 创建OSSClient实例。OSS ossClient = new OSSClientBuilder().build(endpoint, credentialsProvider);try {InputStream inputStream = new FileInputStream(filePath);// 创建PutObjectRequest对象。PutObjectRequest putObjectRequest = new PutObjectRequest(bucketName, objectName, inputStream);// 创建PutObject请求。PutObjectResult result = ossClient.putObject(putObjectRequest);} catch (OSSException oe) {System.out.println("Caught an OSSException, which means your request made it to OSS, "+ "but was rejected with an error response for some reason.");System.out.println("Error Message:" + oe.getErrorMessage());System.out.println("Error Code:" + oe.getErrorCode());System.out.println("Request ID:" + oe.getRequestId());System.out.println("Host ID:" + oe.getHostId());} catch (ClientException ce) {System.out.println("Caught an ClientException, which means the client encountered "+ "a serious internal problem while trying to communicate with OSS, "+ "such as not being able to access the network.");System.out.println("Error Message:" + ce.getMessage());} finally {if (ossClient != null) {ossClient.shutdown();}}}
} 注意：需配置环境变量，然后修改为自己的配置！！
①添加系统环境变量，即你的AccesskKyId和accessKeySecret
②修改Demo里的endpoint、bucketName、objectName和filePath
只需修改这四个用于测试，运行Demo，查看OSS，上传成功！
四.集成OSS（运用于项目中）
1. 在yml文件配置自定义阿里云OSS信息
①在AliOSSProperties类中，先使用@ConfigurationProperties自动注入到yml中
import lombok.Data;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;@Data
@Component
@ConfigurationProperties(prefix = "aliyun.oss")
public class AliOSSProperties {private String endpoint;private String accessKeyId;private String accessKeySecret;private String bucketName;
}②然后在yml文件中配置阿里云OSS
2.编写阿里云工具类（官方代码改编）
import com.aliyun.oss.OSS;
import com.aliyun.oss.OSSClientBuilder;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.stereotype.Component;
import org.springframework.web.multipart.MultipartFile;
import java.io.*;
import java.util.UUID;/*** 阿里云 OSS 工具类*/
@Component
@ConfigurationProperties
public class AliOSSUtils {@Autowiredprivate AliOSSProperties aliOSSProperties;/*** 实现上传图片到OSS*/public String upload(MultipartFile file) throws IOException {//获取阿里云OSS参数String endpoint = aliOSSProperties.getEndpoint();String accessKeyId = aliOSSProperties.getAccessKeyId();String accessKeySecret = aliOSSProperties.getAccessKeySecret();String bucketName = aliOSSProperties.getBucketName();// 获取上传的文件的输入流InputStream inputStream = file.getInputStream();// 避免文件覆盖String originalFilename = file.getOriginalFilename();String fileName = UUID.randomUUID().toString() + originalFilename.substring(originalFilename.lastIndexOf("."));//上传文件到 OSSOSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);ossClient.putObject(bucketName, fileName, inputStream);//文件访问路径String url = endpoint.split("//")[0] + "//" + bucketName + "." + endpoint.split("//")[1] + "/" + fileName;// 关闭ossClientossClient.shutdown();return url;// 把上传到oss的路径返回}}3.编写文件上传类（接口）
import com.itheima.pojo.Result;
import com.itheima.utils.AliOSSUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;import java.io.IOException;@Slf4j
@RestController
public class UploadController {//注入阿里云工具类@Autowiredprivate AliOSSUtils aliOSSUtils;@PostMapping("/upload")public Result upload(MultipartFile image) throws IOException {log.info("文件上传，文件名：{}", image.getOriginalFilename());//调用阿里云OSS工具类进行文件上传String url = aliOSSUtils.upload(image);log.info("文件上传完成，文件访问的url：{}", url);return Result.success(url);}
}至此。后端上传文件至阿里云的代码完成！！