Spring/Mockito JUnit测试空指针异常

Question

尝试让JUnit与mockito测试一起工作，并在我的测试中获得NPE。我想验证一下，当调用createRegistrant（registrationDTO）时，紧接着调用了saveUpdateRegistration（Registration reg）方法。我觉得奇怪的一个问题是，在Mockito上。验证（registrationServiceImpl，Mockito.times（1））。创建注册人（registrationDTO） 方法？IntelliJ只建议界面中的方法？

我的测试代码如下：

@RunWith(MockitoJUnitRunner.class)
public class RegistrationServiceImplTest {

    @InjectMocks
    private RegistrationServiceImpl registrationServiceImpl;

    @Mock
    private RegistrationDTO registrationDTO;

    @Mock
    private Registration registration;


    @Before
    public void setup() {
        registrationDTO.seteId("abc123");
        registrationDTO.setTech("AWS");
        registrationDTO.setFirstName("Bob");
        registrationDTO.setLastName("Tom");

    }


    @Test
    public void createRegistrant() throws Exception {
//        Mockito.when(registrationServiceImpl.createRegistrant(registrationDTO)).thenReturn(registrationDTO);
        Mockito.when(registrationServiceImpl.createRegistrant(registrationDTO)).thenReturn(registrationDTO);
        registrationServiceImpl.createRegistrant(registrationDTO);
        Mockito.verify(registrationServiceImpl, Mockito.times(1)).createRegistrant(registrationDTO);
    }

下面是我正在测试的代码：

package com.TechODex.service;

import com.TechODex.dto.RegistrationDTO;
import com.TechODex.model.Registration;
import com.TechODex.dao.RegistrationDAO;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.util.List;

@Service
@Transactional
public class RegistrationServiceImpl implements RegistrationService {

    @Autowired
    private RegistrationDAO registrationDAO;

    public RegistrationDTO createRegistrant(RegistrationDTO reg) {
        saveUpdateRegistration(setDTOToModel(reg));
        return reg;
    }
    public void deleteRegistrant(Long id) { deleteUserRegistrant(id); }
    public List<Registration> findAllRegistrant(String tech) { return findAllRegistrantDAO(tech);}
    public List<Registration> findAllTech() { return findAllTechDAO();}


    private Registration setDTOToModel(RegistrationDTO dto){
        Registration registration = new Registration();

        registration.setFirstName(dto.getFirstName());
        registration.setLastName(dto.getLastName());
        registration.seteId(dto.geteId());
        registration.setTech(dto.getTech());

        return registration;
    }

    private void saveUpdateRegistration(Registration reg){ registrationDAO.save(reg);}

}

Answer 1

这里有几个问题。

首先，您不模拟RegstrationDAO。这将导致它在测试中的类中为null。接下来，RegstrationService不是模拟，但您尝试在和验证时使用对其进行验证。最后，RegstrationDTO被模拟，因此对中的设置器的调用没有效果。

您的测试应该如下所示：

@RunWith(MockitoJUnitRunner.class)
public class RegistrationServiceImplTest {

    @InjectMocks
    private RegistrationServiceImpl registrationServiceImpl;

    @Mock
    private RegistrationDAO registrationDAO;

    private RegistrationDTO registrationDTO;
    private Registration registration;

    @Before
    public void setup() {
        registration = new Registration();
        registration.seteId("abc123");
        registration.setTech("AWS");
        registration.setFirstName("Bob");
        registration.setLastName("Tom");

        registrationDTO = new RegistrationDTO();
        registrationDTO.seteId("abc123");
        registrationDTO.setTech("AWS");
        registrationDTO.setFirstName("Bob");
        registrationDTO.setLastName("Tom");
    }

    @Test
    public void createRegistrant() throws Exception {
        final RegistrationDTO result = registrationServiceImpl.createRegistrant(registrationDTO);
        assertSame(registrationDTO, result);        

        verify(registrationDAO).save(eq(registration));
    }
}

假设注册有一个实现的equals方法，其中比较设置的字段。如果没有，则需要使用参数捕获器。