How to convert S3object to Observable

Question

I'm trying to implement a method with RxJava and Vert.x framework.

The method has Observable<String> as its return type, but when fetching some data from S3 bucket within the method bogy, it returns S3Object .

Now, I have to covert S3Object to Observable<string> . (I store JSON like abc.json in S3 bucket).

 public Observable<String> getCustomerFroms3(String orderId) {

    AWSCredentials credentials = new BasicAWSCredentials (
           "*************MIIVCCCA",
            "az4aBUp58x&&&&&&&&&&&&&&&&&&&3gUTw"
    );
    AmazonS3 s3client = AmazonS3ClientBuilder
            .standard()
            .withCredentials(new AWSStaticCredentialsProvider (credentials))
            .withRegion(Regions.AP_SOUTH_1)
            .build();

    String bucketName = "database8";
    S3Object s3Object = s3client.getObject(bucketName,orderId);
    System.out.println(s3Object);

}

How I could convert S3Object to Observable ?

Answer 1

A straightforward approach would be to use the Observable factory method to create simple instance out of the S3Object content:

public Observable<String> getCustomerFroms3(String orderId) {
    return Observable.create(
          s -> {
              try {
                  AWSCredentials credentials = new BasicAWSCredentials (
                        "*************MIIVCCCA",
                        "az4aBUp58x&&&&&&&&&&&&&&&&&&&3gUTw"
                  );
                  AmazonS3 s3client = AmazonS3ClientBuilder
                        .standard()
                        .withCredentials(new AWSStaticCredentialsProvider (credentials))
                        .withRegion(Regions.AP_SOUTH_1)
                        .build();

                  S3Object s3Object = s3client.getObject("database8", orderId);
                  s.onNext(IOUtils.toString(s3Object.getObjectContent()));
                  s.onComplete();
              } catch (Exception e) {
                  s.onError(e);
              }
          }
    );
}

Note that this is only to demonstrate the approach to create the Observable instance and should not be considered as an optimal option.