Java Mockito 空指针异常
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Mockito NullPointerException
提问by Anuj
I followed what @hoaz suggested. However, I am getting nullpointer exception
我遵循了@hoaz 的建议。但是，我收到空指针异常
@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)
}
}
In my Code it's like this:
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())
}
}
I also notice that DAO was null so I did this(Just to mention, I did the below step to try, I know the difference between springUnit and Mockito or xyz):
我还注意到 DAO 为空，所以我这样做了（只是提一下，我做了以下步骤来尝试，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内容。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)
}
参考了这个问题：
How do I mock external method call with Mockito
回答by John B
You haven't mocked the behavior of getIdin externalDependencyObjecttherefore it is returning nulland giving you the NPE when toString()is called on that null.
您还没有嘲笑getIdin的行为，externalDependencyObject因此它正在返回null并在toString()被调用时为您提供 NPE null。
You need a when(externalDependencyObject.getId()).then...
你需要一个 when(externalDependencyObject.getId()).then...
