Java EE 6 Pocket Guide

Chapter 9. RESTful Web Services

RESTful web services are defined as JSR 311, and the complete specification can be downloaded from http://jcp.org/aboutJava/communityprocess/mrel/jsr311/index.html.

REST is an architectural style of services that utilizes web standards. Web services designed using REST are called RESTful web services. The main principles of RESTful web services are:

• Everything can be identified as a resource and each resource is uniquely identifiable using a URI.

• A resource can be represented in multiple formats, defined by a media type. The media type will provide enough information on how the requested format needs to be generated. Standard methods are defined for the client and server to negotiate on the content type of the resource.

• Use standard HTTP methods to interact with the resource: GET to retrieve a resource, POST to create a resource, PUT to update a resource, and DELETE to remove a resource.

• Communication between the client and the endpoint is stateless. All the associated state required by the server is passed by the client in each invocation.

Java API for RESTful web services (JAX-RS) defines a standard annotation-driven API that helps developers build a RESTful web service in Java. The standard principles of REST, such as identifying a resource as a URI, a well-defined set of methods to access the resource, and multiple representation formats of a resource, can be easily marked in a POJO using annotations.

Simple RESTful Web Services

A simple RESTful web service ...