The new features of JAX RS 2.0 are the asynchronous calls.
The processing demands on the server work normally in synchronous mode, which means that the client connection of a request is processed by a single thread made available from a container. Once the thread that processed the request comes back to the container, the container can be safely be assumed that the processing of the request is over and that the client connection can be released safely along with all the resources associated with the connection. This model is generally sufficient to process the requests whose execution of resources to process requires a relatively short time.
However, in cases where the execution of an operation on a resource requires much time to calculate the result, a server-side model of asynchronous processing should be used. In this model, there can be no association between...