将图像和视频上传到（S3、CloudFront 等）的服务

Question

我正在寻找从我的移动应用程序（前端）上传视频和图像的服务。我听说过 Amazon S3 和 CloudFront。我正在寻找一种可以存储它们的服务，并且还能够检查它们是否满足某些条件（例如，每张图片的最大文件大小为 3MB），如果文件不满足，则向客户端返回错误标准。 Amazon S3 或 CloudFront 是否提供此功能？如果没有，还有其他推荐的服务吗？

Answer 1

您可以使用 AWS 开发工具包。下面是 Java 版本的示例（亚马逊提供了不同语言的 SDK）：

/**
 * It stores the given file name in S3 and returns the key under which the file has been stored
 * @param resource
 * @param bucketName
 * @return
 */
public String storeProfileImage(File resource, String bucketName, String username) {

    String resourceUrl = null;

    if (!resource.exists()) {
        throw new IllegalArgumentException("The file " + resource.getAbsolutePath() + " doesn't exist");

    }

    long lengthInBytes = resource.length();

    //For demo purposes. You should use a configurable property for the max size
    if (lengthInBytes > (3 * 1024)) {
        //Your error handling here
    }

    AccessControlList acl = new AccessControlList();
    acl.grantPermission(GroupGrantee.AllUsers, Permission.Read);

    String key = username + "/profilePicture." + FilenameUtils.getExtension(resource.getName());

    try {
        s3Client.putObject(new PutObjectRequest(bucketName, key, resource).withAccessControlList(acl));
        resourceUrl = s3Client.getResourceUrl(bucketName, key);
    } catch (AmazonClientException ace) {
        LOG.error("A client exception occurred while trying to store the profile" +
                " image {} on S3. The profile image won't be stored", resource.getAbsolutePath(), ace);
    }

    return resourceUrl;

}

您还可以执行其他操作，例如在存储图像之前检查存储桶是否存在

/**
 * Returns the root URL where the bucket name is located.
 * <p>Please note that the URL does not contain the bucket name</p>
 * @param bucketName The bucket name
 * @return the root URL where the bucket name is located.
 */
public String ensureBucketExists(String bucketName) {

    String bucketUrl = null;

    try {
        if (!s3Client.doesBucketExist(bucketName)) {
            LOG.warn("Bucket {} doesn't exists...Creating one");
            s3Client.createBucket(bucketName);
            LOG.info("Created bucket: {}", bucketName);
        }
        bucketUrl = s3Client.getResourceUrl(bucketName, null) + bucketName;
    } catch (AmazonClientException ace) {
        LOG.error("An error occurred while connecting to S3. Will not execute action" +
                " for bucket: {}", bucketName, ace);
    }


    return bucketUrl;
}