Jakarta RESTful Web Services, (JAX-RS; formerly Java API for RESTful Web Services) is a Jakarta EEAPI specification that provides support in creating web services according to the Representational State Transfer (REST) architectural pattern.[1] JAX-RS uses annotations, introduced in Java SE 5, to simplify the development and deployment of web service clients and endpoints.
From version 1.1 on, JAX-RS is an official part of Java EE 6. A notable feature of being an official part of Java EE is that no configuration is necessary to start using JAX-RS. For non-Java EE 6 environments a small entry in the web.xmldeployment descriptor is required.
Specification
JAX-RS provides some annotations to aid in mapping a resource class (a POJO) as a web resource. The annotations use the Java packagejakarta.ws.rs (previously was javax.ws.rs but was renamed on May 19, 2019[2]). They include:
@Path specifies the relative path for a resource class or method.
@GET, @PUT, @POST, @DELETE and @HEAD specify the HTTP request type of a resource.
@Consumes specifies the accepted request Internet media types.
In addition, it provides further annotations to method parameters to pull information out of the request. All the @*Param annotations take a key of some form which is used to look up the value required.
@PathParam binds the method parameter to a path segment.
@QueryParam binds the method parameter to the value of an HTTP query parameter.
@HeaderParam binds the method parameter to an HTTP header value.
@CookieParam binds the method parameter to a cookie value.
@FormParam binds the method parameter to a form value.
@DefaultValue specifies a default value for the above bindings when the key is not found.
@Context returns the entire context of the object (for example @Context HttpServletRequest request).
JAX-RS 2.0
In January 2011 the JCP formed the JSR 339 expert group to work on JAX-RS 2.0. The main targets are (among others) a common client API and support for Hypermedia following the HATEOAS-principle of REST. In May 2013, it reached the Final Release stage.[3]
On 2017-08-22 JAX-RS 2.1[4] specification final release was published.
Main new supported features include
server-sent events,
reactive clients,
and JSON-B.[5]
Jello-Framework, Java Application Framework optimized for Google App Engine, including a powerful RESTful engine and comprehensive Data Authorization model.
