Editing REST (section)

====Implementing a Restful Service with JAX-RS====
* implement an empty class with annoation like
 @javax.ws.rs.ApplicationPath("/rest")
 public class JaxRsActivator extends javax.ws.rs.Application { }
* reuse BaseEntityService as base class of project uweheuer_new and define subclass like
 @javax.ws.rs.Path("/notes")
 @javax.ejb.Stateless // This is a stateless service, so a single shared instance can be used in this case.
 public class NotesService extends BaseEntityService<Note>

The return type obviously depends on the purpose of the API. The procudure to set the return value depends of the outcome of API:
#Http codes: 404 requested resource does not exist, 400 the request is semantically incorrect, 401 the user is not authorized, 500 there is a problem with the database connection) via e.g.
 return Response.status(Response.Status.NOT_FOUND).entity("...").build();
#Http code 201 created
 

* annotate changing services like and return response applying the following patterns
 @javax.ws.rs.POST
 @javax.ws.rs.Consumes(MediaType.APPLICATION_JSON)
 public Response saveNote(Note note)
 {
   return Response.ok(); // creates a response with a status of 200 and an empty entity body.
   return Response.ok(entity).build(); // creates a response with a status of 200, stores the supplied object in the
                                       // responses entity body, and determines the entities media type by introspecting the object
   return Response.noContent().build(); // reating a response with a 204 status (no content)
 }