Mockito NullPointerException

Question

我遵循了@hoaz 的建议。但是，我得到空指针异常

@RunWith(MockitoJUnitRunner.class)
public class GeneralConfigServiceImplTest  {

@InjectMocks private GeneralConfigService generalConfigService;
@Mock private SomeDao someDao;
@Mock private ExternalDependencyClass externalDependencyObject 

@Test
public void testAddGeneralConfigCallDAOSuccess() {
    when(someDao.findMe(any(String.Class))).thenReturn(new ArrayList<String>(Arrays.asList("1234")));

    //println works here, I am able to get collection from my mocked DAO

    // Calling the actual service function
    generalConfigService.process(externalDependencyObject)
    }
}

在我的代码中是这样的：

import com.xyz.ExternalDependencyClass;

public class  GeneralConfigService{

private SomeDao someDao;

public void process(ExternalDependencyClass externalDependencyObject){

// function using Mockito 
Collection<String> result = someDao.findMe(externalDependencyObject.getId.toString())
    }
}

我也注意到 DAO 是空的，所以我这样做了（顺便提一下，我做了下面的步骤来尝试，我知道 springUnit 和 Mockito 或 xyz 之间的区别）：

@Autowired
private SomeDao someDao;

---

@John B 解决方案解决了我的问题。但是，我想提一下对我不起作用的东西。这是我更新的单元测试

@Test
public void testAddGeneralConfigCallDAOSuccess() {
    /*
    This does not work
    externalDependencyObject.setId(new ExternalKey("pk_1"));
    // verify statement works and I thought that the class in test when call the getId 
    // it will be able to get the ExternalKey object
    //verify(externalDependencyObject.setId(new ExternalKey("pk_1")));
    */

    // This works
    when(externalDependencyObject.getId()).thenReturn(new ExternalKey("pk_1"));
    when(someDao.findMe(any(String.Class))).thenReturn(new ArrayList<String>(Arrays.asList("1234")));

    ....
    // Calling the actual service function
    generalConfigService.process(externalDependencyObject)
    }

---

在中引用了这个问题：

How do I mock external method call with Mockito

How do I set a property on a mocked object using Mockito?

Answer 1

您没有嘲笑getId 在externalDependencyObject 中的行为，因此它返回null 并在toString() 调用null 时为您提供NPE。

你需要一个when(externalDependencyObject.getId()).then...