Unit test for class with injected bean

I have a class for rest calls. This class holds a bean injection. What I want to now is write a unit test for the method that is using the injected class. However I can't seem to get this working. Is anyone able to tell me what is going wrong?

The rest class looks like this

@Path("/rekeningrijders")
@RequestScoped
public class RekeningrijderService {

@Inject
UserService userservice;

@GET
@Path("/status")
@Produces({MediaType.APPLICATION_XML})
public String getMonitoring() {
    return "<Status><Note>ALLES-IS-OK-HIER</Note></Status>";
}

@GET
@Path("/users")
@Produces({MediaType.APPLICATION_JSON})
    public List<User> getUsers() {
        return userservice.findAll();
    }

}

The UserService looks like this

@Stateless
public class UserService {

    @PersistenceContext(name = "RekeningrijdersApplicatiePU")
    EntityManager em;

    ......

public List<User> findAll() {
        CriteriaQuery cq = em.getCriteriaBuilder().createQuery();
        cq.select(cq.from(User.class));
        try {
            return em.createQuery(cq).getResultList();
        } catch (NoResultException ex) {
            Logger.getLogger(UserService.class.getName()).log(Level.SEVERE, null, ex);
            return null;
        }
    }
}

What I did so for in my unit test is the

public class RestTest {
    private final RekeningrijderService rekeningrijdersService = new RekeningrijderService();
    private final RekeningrijderService t2 = Mockito.mock(RekeningrijderService.class);

    @InjectMocks
    UserService userService;

    @Before
    public void setUp(){
        RestAssured.baseURI = "http://ift.tt/28VIvxu";
        RestAssured.basePath = "RekeningrijdersApplicatie/api/rekeningrijders";
    }

    @Test
    public void testStatus(){
        Response response = when().get("/status").then().contentType(ContentType.XML).extract().response();
        String responseBody = response.getBody().asString();
        assertEquals("<Status><Note>ALLES-IS-OK-HIER</Note></Status>", rekeningrijdersService.getMonitoring());
        assertEquals("<Status><Note>ALLES-IS-OK-HIER</Note></Status>", responseBody);
    }

    @Test
    public void testGetUsers(){
        Response response = when().get("/users").then().contentType(ContentType.JSON).extract().response();
        String responseBody = response.getBody().asString();
        responseBody = "[]";
        String a = t2.getUsers().toString();
        assertEquals(responseBody, t2.getUsers().toString());
    }

the problem lays in the testGetUser method. As you can tell I'm messing with it but when I use the rekeningrijdersService object it will return a null pointer exception. When I use a mocked object it will return an empty string while it should hold 1 user.

Could anyone possible tell me what I'm doing wrong?