Amazon recently announced the AWS SDK for java.
SDK or a java api is very much needed – especially if you are writing your automation scripts in groovy. We have tried multiple java apis in our scripts including JetS3t and Typica. These apis were really helpful, but they only supported some of the AWS services and were not up to date (for obvious reasons). Having one java api that can support all of AWS technologies was definitely the need of the hour. I am sure Amazon will keep it updated as new services are released. They have the necessary resources to do so.
Furthermore, Amazon has also uploaded the SDK to the maven repository.
You can use the following dependency in your pom.xml:
The java doc for the SDK is hosted at http://docs.amazonwebservices.com/AWSJavaSDK/latest/javadoc/index.html
Amazon has also opened the SDK source code for all. They have mirrored the SDK code repository at github. You can look at the SDK code at http://github.com/amazonwebservices/aws-sdk-for-java