Mockito testing service layer - spring-mvc

Question

I'm new to Mockito and trying to test my service layer. My DAO layer is #Autowired in service and Hibernate is also autowired. Hibernate is not loading while testing. I always get NullPointerException. Here is my code:
EmployeeService (Interface)
package com.spring.crud.service;
import java.util.List;
import com.spring.crud.entity.Employee;
public interface EmployeeService {
Employee save(Employee employee);
boolean update(Employee employee);
Employee find(Integer id);
List<Employee> getEmployees();
boolean remove(Integer id);
}
EmployeeServiceImpl (Class)
package com.spring.crud.service;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import com.spring.crud.dao.EmployeeDAO;
import com.spring.crud.entity.Employee;
#Service
public class EmployeeServiceImpl implements EmployeeService {
#Autowired
private EmployeeDAO dao;
public Employee save(Employee employee) {
return dao.save(employee);
}
public boolean update(Employee employee) {
return dao.update(employee);
}
public Employee find(Integer id) {
return dao.find(id);
}
public List<Employee> getEmployees() {
return dao.getEmployees();
}
public boolean remove(Integer id) {
return dao.remove(id);
}
}
EmployeeDAO (Interface)
package com.spring.crud.dao;
import java.util.List;
import com.spring.crud.entity.Employee;
public interface EmployeeDAO {
Employee save(Employee employee);
boolean update(Employee employee);
Employee find(Integer id);
List<Employee> getEmployees();
boolean remove(Integer id);
}
EmployeeDAOImpl (Class)
package com.spring.crud.dao;
import java.util.List;
import javax.transaction.Transactional;
import org.hibernate.Query;
import org.hibernate.Session;
import org.springframework.stereotype.Repository;
import com.spring.crud.entity.Employee;
#Transactional
#Repository
public class EmployeeDAOImpl extends HibernateUtil implements EmployeeDAO{
public Employee save(Employee employee) {
Session session = getCurrentSession();
session.save(employee);
return employee;
}
public boolean update(Employee employee) {
Session session = getCurrentSession();
session.update(employee);
return false;
}
public Employee find(Integer id) {
Session session = getCurrentSession();
Employee employee = (Employee)session.get(Employee.class, id);
return employee;
}
public List<Employee> getEmployees() {
Session session = getCurrentSession();
Query query = session.createQuery("from Employee");
#SuppressWarnings("unchecked")
List<Employee> employees = (List<Employee>)query.list();
return employees;
}
public boolean remove(Integer id) {
Session session = getCurrentSession();
Employee employee = (Employee)session.get(Employee.class, id);
if(employee!=null){
session.delete(employee);
return true;
}
return false;
}
}
HibernateUtil
package com.spring.crud.dao;
import javax.annotation.PostConstruct;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;
public class HibernateUtil extends HibernateDaoSupport{
#Autowired
private SessionFactory sessionFactory;
#PostConstruct
public void init() {
setSessionFactory(sessionFactory);
}
public Session getCurrentSession() {
return sessionFactory.getCurrentSession();
}
}
EmployeeServiceTest (Test class)
package com.spring.crud.test;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertTrue;
import static org.mockito.Matchers.any;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import org.junit.Before;
import org.junit.Test;
import org.mockito.MockitoAnnotations;
import org.mockito.Spy;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
import org.springframework.test.context.ContextConfiguration;
import com.spring.crud.config.WebConfig;
import com.spring.crud.dao.EmployeeDAO;
import com.spring.crud.dao.EmployeeDAOImpl;
import com.spring.crud.entity.Employee;
import com.spring.crud.service.EmployeeService;
import com.spring.crud.service.EmployeeServiceImpl;
#ContextConfiguration(classes = {WebConfig.class})
public class EmployeeServiceTest {
private EmployeeDAO employeeDAO;
private EmployeeService employeeService = new EmployeeServiceImpl();
#Spy
List<Employee> employees = new ArrayList<Employee>();
#Before
public void setup() {
MockitoAnnotations.initMocks(this);
employeeDAO = mock(EmployeeDAOImpl.class);
}
#Test
public void listEmployees() {
}
#Test
public void create() {
Employee employee = new Employee();
employee.setDateOfBirth(new Date());
employee.setGender("male");
employee.setName("Ashutosh");
when(employeeDAO.save(any(Employee.class)))
.thenAnswer(new Answer<Employee>() {
public Employee answer(InvocationOnMock invocation) throws Throwable {
Employee employee = (Employee) invocation.getArguments()[0];
employee.setId(1);
return employee;
}
});
assertNull(employee.getId());
employee = employeeService.save(employee);
assertNotNull(employee.getId());
assertTrue(employee.getId()>0);
}
#Test
public void edit() {
}
#Test
public void update() {
}
#Test
public void remove() {
}
}
I can't find much on this on the internet.

Answer 1

Just because you create a mock employee DAO in your test doesn't mean that your service will use it. It won't. When you do
new EmployeeServiceImpl();
you create an instance of the service, and its DAO field is left uninitialized (so null).
Use constructor injection, and pass the mock DAO to the service constructor:
public class EmployeeServiceImpl implements EmployeeService {
private EmployeeDAO dao;
#Autowired
public EmployeeServiceImpl(EmployeeDAO dao) {
this.dao = dao;
}
...
}
And/or at least use Mockito annotations correctly:
#Mock
private EmployeeDAO employeeDAO;
#InjectMocks
private EmployeeServiceImpl employeeService;
#Before
public void setup() {
MockitoAnnotations.initMocks(this);
}

Answer 2

OK, I found some fixes and now the test runs.
First, I fixed the HibernateUtil
package com.spring.crud.dao;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.springframework.beans.factory.annotation.Autowired;
public class HibernateUtil{
#Autowired
private SessionFactory sessionFactory;
public Session getCurrentSession() {
return sessionFactory.getCurrentSession();
}
}
This is the EmployeeServiceTest class
package com.spring.crud.test;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.mockito.Matchers.any;
import static org.mockito.Mockito.when;
import java.util.Date;
import org.junit.Before;
import org.junit.Test;
import org.mockito.InjectMocks;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.mockito.invocation.InvocationOnMock;
import org.mockito.stubbing.Answer;
import org.springframework.test.context.ContextConfiguration;
import com.spring.crud.config.WebConfig;
import com.spring.crud.dao.EmployeeDAO;
import com.spring.crud.entity.Employee;
import com.spring.crud.service.EmployeeServiceImpl;
#ContextConfiguration(classes = {WebConfig.class})
public class EmployeeServiceTest {
#Mock
private EmployeeDAO employeeDAO;
#InjectMocks
private EmployeeServiceImpl employeeService;
#Before
public void setup() {
MockitoAnnotations.initMocks(this);
}
#Test
public void listEmployees() {
}
#Test
public void create() {
Employee employee = new Employee();
employee.setDateOfBirth(new Date());
employee.setGender("male");
employee.setName("Ashutosh");
when(employeeDAO.save(any(Employee.class)))
.thenAnswer(new Answer<Employee>() {
public Employee answer(InvocationOnMock invocation) throws Throwable {
Employee employee = (Employee) invocation.getArguments()[0];
employee.setId(10);
return employee;
}
});
assertNull(employee.getId());
employee = employeeService.save(employee);
System.out.println("Id = " + employee.getId());
assertNotNull(employee);
assertEquals((Integer)10, (Integer)employee.getId());
}
#Test
public void edit() {
}
#Test
public void update() {
}
#Test
public void remove() {
}
}