REST in Java

Most of my work with Web Services has been with SOAP-based Web Services. However, there is an alternative, called REST.

There is Java library for RESTful Web Services, called JAX-RS.

JAX-RS RESTful principles are:
- assign everything an ID
- link things together
- use common set of methods
- allow multiple representations
- stateless communications

Classes and methods are annotated to generate REST service.
Here is an example:

@Path("/atm")
public class AtmService {

    @GET @PATH("/balance")
    @Produces("text/plain")
    public String balance(@QueryParam("card") String card,
                          @QueryParam("pin") String pin) {

        ...
    }

...

There also annotations for using HTTP POST (@POST) and specifying the data type that is consumes (@Consumes).

This example was taken from a Java ONE presentation.