JERSEY

Sun offers a reference implementation for JAX-RS code-named Jersey. Jersey uses a HTTP web server called Grizzly, and the Servlet Grizzly Servlet (com.sun.jersey.spi.container.servlet.ServletContainer) handles the requests to Grizzly. You can develop production-quality JAX-RS applications today using Jersey, which implements all the APIs and provides all the necessary annotations for creating RESTful web services in Java quickly and easily. Beyond the set of annotations and features defined by JAX-RS, Jersey provides additional features through its own APIs, such as the Jersey Client API.

You can download Jersey separately or acquire it as a bundle with NetBeans 6.5 and GlassFish V3.

Developing RESTful Web Services Using JAX-RS
The classes and interfaces you use for creating RESTful web services with JAX-RS are available in the following packages:
javax.ws.rs
javax.ws.rs.core
javax.ws.rs.ext

I'm going to provide link to previous post for Jersey example and will write about Sprint rest template in my next post...

Jersey Example