1.使用MultipartFile file接收，不能加requestBody注解
2.file.getOriginalFilename()获取文件名称，file.getInputStream()获取文件流
3.上传oss

public static String putObject(String fileName, InputStream inputStream) {

    // 工具类获取值
    String endpoint = OssProperties.END_POIND;
    String accessKeyId = OssProperties.ACCESS_KEY_ID;
    String accessKeySecret = OssProperties.ACCESS_KEY_SECRET;
    String bucketName = OssProperties.BUCKET_NAME;

    // 创建OSS实例
    OSS ossClient = new OSSClientBuilder().build(endpoint, accessKeyId, accessKeySecret);

    try {
        // 创建PutObjectRequest对象
        PutObjectRequest putObjectRequest = new PutObjectRequest(bucketName, fileName, 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");

        PutObjectResult result = ossClient.putObject(putObjectRequest);
        // 如果上传成功，则返回200
        if (200 == result.getResponse().getStatusCode()) {
            // 把上传之后文件路径返回
            // 需要把上传到阿里云oss路径手动拼接出来
            return AccouuntConstants.HTTPS_URL + bucketName + AccouuntConstants.DROP + endpoint + AccouuntConstants.BACKSLASH + fileName;
        }

    } catch (OSSException | ClientException oe) {
        log.error("ali oss catch oe:{}", ThrowableUtil.getLastStackTrace(oe, 10));
    } finally {
        if (ossClient != null) {
            ossClient.shutdown();
        }
    }
    return null;
}