JAVA REST - HTTP Status 405 - Method Not Allowed

{
"password":"456",
"userName":"julia.andrade"
}

package rest;

import java.util.List;

import javax.ws.rs.Consumes;
import javax.ws.rs.DELETE;
import javax.ws.rs.GET;
import javax.ws.rs.POST;
import javax.ws.rs.Path;
import javax.ws.rs.PathParam;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;

import dao.UserDAO;
import model.User;

@Path("/user")
public class UserService {
	private static final String CHARSET_UTF8 = ";charset=utf-8";

	@POST
	@Path("/add")
	@Consumes(MediaType.APPLICATION_JSON + CHARSET_UTF8)
	@Produces(MediaType.TEXT_PLAIN)
	public String addUser(User user){
		String result;
		
		try{
			UserDAO.getInstance().addUser(user);
			result = "OK";
		}catch(Exception e){
			e.printStackTrace();
			result = "ERROR";
		}
		
		return result;
	}
}

package dao;

import java.util.ArrayList;
import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

import model.*;

public class UserDAO {
	private static UserDAO instance;
	private SessionFactory sessionFactory;
	
	public static UserDAO getInstance(){
		if (instance == null){
			instance = new UserDAO();
		}

		return instance;
	}

	private UserDAO() {
		sessionFactory = getEntityManager();
	}

	private SessionFactory getEntityManager() {
		return new Configuration().configure().buildSessionFactory();
	}

	public void addUser(final User user) {
		Session session = sessionFactory.openSession();;
		session.beginTransaction();	
		
		session.persist(user);
		session.getTransaction().commit();
		
		session.close();
	}

}