Jersey Service and Persistence Layers

Question

I'm am developing a simple Question and Answer service (Jersey JAX-RS). With this service, I've come up with the following resource so far (might increase).

• GET|POST -------------/questions
• GET|PUT|DELETE -- /questions/{id}
• GET|POST ------------ /questions/{id}/answers
• GET|PUT|DELETE - /questions/{questionId}/answers/{answerId}

This is my resource class with caters all of the above paths.

@Path("/questions")
public class QuestionResource {
    @Inject
    private QuestionService questionService;

    @GET
    ...<list of questions>

    @POST
    ...<a new question>

    @Path("{id}")
    ...<a question>

    @PUT    
    @Path("{id}")
    ...<update a question>

    @DELETE
    @Path("{id}")
    ...<delete a question>

    @GET
    @Path("{id}/answers")
    ...<list of answers>

    @POST
    @Path("{id}/answers")
    ...<a new answer for a question>

    @GET
    @Path("{questionId}/answers/{answerId}")
    ...<an answer for a question>

    @PUT
    @Path("{questionId}/answers/{answerId}")
    ...<update an answer for a question>

    @DELETE
    @Path("{questionId}/answers/{answerId}")
    ...<delete an answer for a question>
}

This has corresponding service and persistence layers - QuestionService/QuestionServiceImpl and QuestionRepository/QuestionRepositoryImpl. But, I'm bit confused as to which service and reposipotory I should put the methods that would be called to process the request of the last five. Should I put them all also to Question service and repository or to another classess - Answer service and repository?

I'm considering the latter due to Many-To-One relationship of Answer and Question (JPQL NamedQuery - SELECT a FROM Answer a WHERE a.question.id = :questionId). It would mean that I would have also AnswerService aside from QuestionService in my QuestionResource. Would that be alright.

Please enlighten me. Thank you.

Answer 1

• In restful APIs everything is a resource and when it comes to relation you consider a main resource and other resources or in another words resource and subresource.

• In your case the answer is the subresource because your answer resource can't be a main resource without question or in another words which one of your resources depends on the other one. Absolutely your answer depends on question