如何从Amazon Cognito提供的凭据访问S3存储桶？

Question

我正在使用Amazon S3存储桶上传我的图像。我收到了来自Google的警告邮件，说我的AWS凭证已公开。所以现在我要替换代码，并使用Amazon Cognito。

我无法访问该存储桶。该错误表明访问被拒绝。

这是我的代码：

 credentialsProvider = new CognitoCachingCredentialsProvider(
     context, // get the context for the current activity
     "xxxxxxx", // your AWS Account id
     "ap-southeast-1:3d4e113d-4cd3-47ac-b5ef-xxxxxxxxxx", // your identity pool id
     "arn:aws:iam::xxxxxxxxx:role/Cognito_trackusersUnauth_Role",// an authenticated role ARN
     "arn:aws:iam::xxxxxxxxx:role/Cognito_trackusersAuth_Role", // an unauthenticated role ARN
     Regions.AP_SOUTHEAST_1 //Region
    );

    s3 = new AmazonS3Client(credentialsProvider);
    s3.setEndpoint("s3-ap-southeast-1.amazonaws.com");

这是拒绝访问的地方：

 List<Bucket> buckets = s3.listBuckets();