“Federation is the act of combining data or identities across multiple systems. Federation can be done by a cloud provider or by a cloud broker. A broker has no cloud resources of its own, but matches consumers and providers based on the SLA required by the consumer. The consumer has no knowledge that the broker does not control the resources.” - Cloud computing community

Here is a sample code for creating an AMI from java code, using the Amazon's EC2 aws-java-sdk. I didn't manage to find a good "hello world" example for java, so I post my attempt here. I hope that you can kick-start working on the cloud.
First, you create an instance of the wrapper. Then, you can use it for example like:  createAMInstances(amiId, 1, 3, "mykey", "m1.small", "us-east-1a");