import com.aliyun.oss.OSSClient;
import com.aliyun.oss.model.ObjectMetadata;
import com.aliyun.oss.model.PutObjectResult;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.UUID;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.multipart.MultipartFile;

/**
 * @author jack
 */
@Slf4j
public class AliyunOssClientUtil {

  //阿里云API的内或外网域名
  private static String ENDPOINT;
  //阿里云API的密钥Access Key ID
  private static String ACCESS_KEY_ID;
  //阿里云API的密钥Access Key Secret
  private static String ACCESS_KEY_SECRET;
  //阿里云API的bucket名称
  private static String BACKET_NAME;
  //阿里云API的文件夹名称
  private static String FOLDER;

  //初始化属性
  static {
    ENDPOINT = OSSClientConstants.ENDPOINT;
    ACCESS_KEY_ID = OSSClientConstants.ACCESS_KEY_ID;
    ACCESS_KEY_SECRET = OSSClientConstants.ACCESS_KEY_SECRET;
    BACKET_NAME = OSSClientConstants.BACKET_NAME;
    FOLDER = OSSClientConstants.FOLDER;
  }

  public static OSSClient getOSSClient() {
    return new OSSClient(ENDPOINT, ACCESS_KEY_ID, ACCESS_KEY_SECRET);
  }
  private static String getContentType(String fileName) {
    //文件的后缀名
    String fileExtension = fileName.substring(fileName.lastIndexOf("."));
    if (".bmp".equalsIgnoreCase(fileExtension)) {
      return "image/bmp";
    }
    if (".gif".equalsIgnoreCase(fileExtension)) {
      return "image/gif";
    }
    if (".jpeg".equalsIgnoreCase(fileExtension) || ".jpg".equalsIgnoreCase(fileExtension) || ".png"
        .equalsIgnoreCase(fileExtension)) {
      return "image/jpeg";
    }
    if (".html".equalsIgnoreCase(fileExtension)) {
      return "text/html";
    }
    if (".txt".equalsIgnoreCase(fileExtension)) {
      return "text/plain";
    }
    if (".vsd".equalsIgnoreCase(fileExtension)) {
      return "application/vnd.visio";
    }
    if (".ppt".equalsIgnoreCase(fileExtension) || "pptx".equalsIgnoreCase(fileExtension)) {
      return "application/vnd.ms-powerpoint";
    }
    if (".doc".equalsIgnoreCase(fileExtension) || "docx".equalsIgnoreCase(fileExtension)) {
      return "application/msword";
    }
    if (".xml".equalsIgnoreCase(fileExtension)) {
      return "text/xml";
    }
    //默认返回类型
    return "image/jpeg";
  }

  /**
   * 上传到OSS服务器  如果同名文件会覆盖服务器上的
   *
   * @param instream 文件流
   * @param fileName 文件名称 包括后缀名
   * @return 出错返回"" ,唯一MD5数字签名
   */
  private static void uploadFile2OSSTest(InputStream instream, String fileName,
      OSSClient ossClient) {
    try {
      //创建上传Object的Metadata
      ObjectMetadata objectMetadata = new ObjectMetadata();
      objectMetadata.setContentLength(instream.available());
      objectMetadata.setCacheControl("no-cache");
      objectMetadata.setHeader("Pragma", "no-cache");
      objectMetadata.setContentType(getContentType(fileName.substring(fileName.lastIndexOf("."))));
      objectMetadata.setContentDisposition("inline;filename=" + fileName);
      //上传文件
      ossClient.putObject(BACKET_NAME, FOLDER + fileName, instream, objectMetadata);
    } catch (IOException e) {
      log.error(e.getMessage(), e);
    } finally {
      try {
        if (instream != null) {
          instream.close();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }

  //上传一张图片
  public static String saveImg(MultipartFile multipartFile,OSSClient ossClient){
    // 获取图片名字
    String fileName = multipartFile.getOriginalFilename();
    //防止名字冲突覆盖原有图片
    String uuid = UUID.randomUUID().toString().replace("-", "").toLowerCase();
    fileName=uuid+fileName;
    try {
      InputStream inputStream = multipartFile.getInputStream();
      AliyunOssClientUtil.uploadFile2OSSTest(inputStream, fileName,ossClient);
    } catch (IOException e) {
      e.printStackTrace();
    }
    String  urlName = fileName.substring(fileName.lastIndexOf("\\")+1,fileName.length());
    return "https://" + BACKET_NAME+"."+ENDPOINT+ File.separator + FOLDER +urlName;
  }
}

P.S. 注意阿里云的读取权限,此方法为公读性