https://github.com/aws/aws-sdk-java
https://github.com/aws/aws-sdk-java/tree/master/aws-java-sdk-s3
https://github.com/aws/aws-sdk-java/tree/master/aws-java-sdk-s3/src/main/java/com/amazonaws/services/s3

https://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk-core
https://mvnrepository.com/artifact/com.amazonaws/aws-java-sdk-s3

https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/welcome.html
https://github.com/awsdocs/aws-java-developer-guide/tree/master/doc_source

api
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/index.html
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/regions/Regions.html
    https://github.com/aws/aws-sdk-java/blob/master/aws-java-sdk-core/src/main/java/com/amazonaws/regions/Regions.java
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/package-frame.html
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3.html
    ! doesObjectExists

    ! getObject(GetObjectRequest)
    ! getObject[Acl|Metadata|Retention|Tagging]

    ! listObjects
        (bucketName)
        (bucketName, prefix)
    ! listNextBatchOfObjects
    !
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/model/S3ObjectId.html
    https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/model/S3ObjectIdBuilder.html
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/model/GetObjectRequest.html
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/model/PutObjectRequest.html
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/model/PutObjectResult.html
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/model/ObjectMetadata.html
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/model/ObjectListing.html
    ? delimiter, marker, prefix
    ! commonPrefixes are only present if a delimiter was specified in the original request
https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/model/S3ObjectSummary.html

delimiters and prefixes
    https://docs.aws.amazon.com/AmazonS3/latest/dev/ListingKeysHierarchy.html

credentials
https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/setup-credentials.html
https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/credentials.html

regions
https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/java-dg-region-selection.html

exceptions
https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/java-dg-exceptions.html

logging
https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/java-dg-logging.html

security
https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/security.html
access-control-policies
https://docs.aws.amazon.com/sdk-for-java/v1/developer-guide/java-dg-access-control.html

content length
https://stackoverflow.com/questions/36201759/how-to-set-inputstream-content-length

samples
https://github.com/aws-samples/aws-java-sample/blob/master/src/main/java/com/amazonaws/samples/S3Sample.java