JAXRS

JAX-RS, short for Java API for RESTful Web Services, is a Java specification designed to simplify the development of RESTful web services and clients. It defines a set of annotations and runtime conventions that enable developers to expose Java classes as REST resources and to consume RESTful services.

Resource classes are ordinary Java classes annotated with @Path to bind to a URI path. Methods within the resource can be annotated with HTTP method designators such as @GET, @POST, @PUT, and @DELETE, and with @Produces and @Consumes to declare supported media types. The framework handles the conversion of Java objects to and from representations like JSON or XML via providers.

JAX-RS also provides a client API for invoking REST endpoints from Java applications. It supports asynchronous processing, content negotiation, and parameter binding with annotations such as @PathParam, @QueryParam, and @HeaderParam. It integrates with dependency injection frameworks like CDI and allows the use of providers registered with @Provider to implement message body readers and writers for custom formats.

As a core component of Java EE (later Jakarta EE), JAX-RS has been implemented by multiple runtimes, including Jersey (the reference implementation), RESTEasy, and Apache CXF. The specification has evolved through versions that enhance features such as client and server capabilities, filters, interceptors, and asynchronous processing. With Jakarta EE 9, the namespace transitioned from javax to jakarta, affecting JAX-RS packages while preserving the programming model and usage patterns. See also: Jersey, RESTEasy, Apache CXF.