S3AsyncClient 会在每个区域端点上抛出 java.lang.NullPointer

Question

我正在尝试将文件上传到 ap-southeast-1 区域中的 AWS Bucket，凭证已经过验证并且是正确的。

S3AsyncClientBuilder 为每个区域端点抛出空指针异常。（https://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region）

github 上的一个相关线程在签署区域时遇到问题，但这不是问题，一旦指定了适当的区域。

https://github.com/aws/aws-sdk-java-v2/issues/448

这是访问 AWS Bucket 的类，为了清楚起见，该行已被注释。

public class ObjectUploaderInterfaceImpl implements ObjectUploaderInterface {

  private String AWS_ACCESS_KEY;

  private String AWS_SECRET_KEY;

  private S3AsyncClient s3Client; // Asynchronous Client for Non Blocking IO

  private AwsCredentialsProvider credentials;

  public ObjectUploaderInterfaceImpl(String awsAccessKey, String awsSecretKey) {

    this.AWS_ACCESS_KEY = awsAccessKey;

    this.AWS_SECRET_KEY = awsSecretKey;

    this.credentials = new StaticCredentialsProvider(

        new AwsCredentials(this.AWS_ACCESS_KEY, this.AWS_SECRET_KEY));

    try {

      this.s3Client = S3AsyncClient.builder()

          .credentialsProvider(this.credentials)

          .region(Region.AP_SOUTHEAST_1)

          .endpointOverride(new URI("s3-ap-southeast-1.amazonaws.com"))

          .build(); // Throws Null pointer Exception

    } catch (Exception e) {

      e.printStackTrace();

    }

  }

  @Override

  public CompletableFuture<PutObjectResponse> uploadObject(String filePath, String s3Bucket,

      String s3BucketPath) {

    CompletableFuture<PutObjectResponse> future;

    try {

      future = s3Client.putObject(

          PutObjectRequest.builder()

              .bucket(s3Bucket)

              .key(s3BucketPath)

              .build(),

          AsyncRequestProvider.fromFile(Paths.get(filePath))

      );

      future.whenComplete((resp, err) -> {

        if (resp != null) {

          System.out.println("Response from Server : " + resp);

        } else {

          err.printStackTrace();

        }

        try {

          s3Client.close();

        } catch (Exception e) {

          System.out.println(e);

        }

      });

    } 

  }

}

我不确定是什么原因导致这种情况，自 AWS-SDK 2.0 最近发布以来，文档中提供了一些参考。