Using aws sdk (java 2.x) to access S3/Swift Object Storage

Is Swift Object Storage compatible with the "standard" aws sdk (v. 2.0) ?

Here my code to create a S3Client:
AwsBasicCredentials awsCreds = AwsBasicCredentials.create(
"accessKeyId",
"secretAccessKey");

client = S3Client.builder()
.credentialsProvider(StaticCredentialsProvider.create(awsCreds))
.region(????)
.build();

I found my accessKeyId and secretAccessKey, but I can't set a proper vaue for "region", because it is NOT a string, but an instance of software.amazon.awssdk.regions.Region class, that has a predefined values only (I think I should pass "gra").
Does that mean I cannot use this sdk? Do I have to use the REST API?