Question

I have some interface description in text describing a RESTful webserver. I also have JAX-B annotated objects that I want to push and receive from that interface.

I’m not sure how much support for such a task is already implemented. There is some Jersey thing around, but is that still up to date?

Do I have to define a target URL, open a stream, serialize the xml object (maybe turning it into a string first?), and then write it to the stream?

Or is there some magic method that only expects a URL and the JAX-B object and maybe if I want to PUT,DELETE,POST or GET it?

Answer 1

JAX-RS is what you want to use in this case and Jersey is the reference implementation. JAXB is the default binding layer for JAX-RS. Below is an example of a RESTful service that supports PUT, DELETE, POST, and GET:

package org.example;

import java.util.List;

import javax.ejb.*;
import javax.persistence.*;
import javax.ws.rs.*;
import javax.ws.rs.core.MediaType;

@Stateless
@LocalBean
@Path("/customers")
public class CustomerService {

    @PersistenceContext(unitName="CustomerService",
                        type=PersistenceContextType.TRANSACTION)
    EntityManager entityManager;

    @POST
    @Consumes(MediaType.APPLICATION_XML)
    public void create(Customer customer) {
        entityManager.persist(customer);
    }

    @GET
    @Produces(MediaType.APPLICATION_XML)
    @Path("{id}")
    public Customer read(@PathParam("id") long id) {
        return entityManager.find(Customer.class, id);
    }

    @PUT
    @Consumes(MediaType.APPLICATION_XML)
    public void update(Customer customer) {
        entityManager.merge(customer);
    }

    @DELETE
    @Path("{id}")
    public void delete(@PathParam("id") long id) {
        Customer customer = read(id);
        if(null != customer) {
            entityManager.remove(customer);
        }
    }

    @GET
    @Produces(MediaType.APPLICATION_XML)
    @Path("findCustomersByCity/{city}")
    public List<Customer> findCustomersByCity(@PathParam("city") String city) {
        Query query = entityManager.createNamedQuery("findCustomersByCity");
        query.setParameter("city", city);
        return query.getResultList();
    }

}

Below are links to the full example:

• Part 1 – Data Model
• Part 2 – JPA
• Part 3 – JAXB (using MOXy)
• Part 4 – RESTful Service (using an EJB session bean)