The Java EE 6 release took the first step towards standardizing RESTful web service APIs by introducing a Java API for RESTful web services (JAX-RS).
JAX-RS ensures the portability of REST API code across all Java EE-compliant application servers. The latest version is JAX-RS 2.0, which was released as part of the Java EE 7 platform.
JAX-RS focuses on applying Java annotations to plain Java objects. JAX-RS has annotations to bind specific URI patterns and HTTP operations to specific methods of your Java class. It also has annotations that can help you handle input/output parameters.
As we already said that JAX-RS is a specification; it means we need to have its implementation to run REST API code. Some of the popular JAX-RS implementations available today are:
* Jersey
* RESTEasy
* Apache CXF
