@GET()
 @Path("all")
 @Produces("application/json")
 public Contact[] getAll() {
   return helper
       .getEntityManager()
       .createNamedQuery("Contact.findAll", Contact.class)
       .getResultList()
       .toArray(new Contact[0]);
 }
 @GET()
 @Path("byId")
 @Produces("application/json")
 public Contact[] getbyId(@QueryParam("cid") String cid) {
   return helper
       .getEntityManager()
       .createNamedQuery("Contact.findById", Contact.class)
       .setParameter("cId", new Integer(cid))
       .getResultList()
       .toArray(new Contact[0]);
 }