java Mockito - 无法实例化 @InjectMocks
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Mockito - Cannot instantiate @InjectMocks
提问by Arpit Aggarwal
I have two private fields in my class which I am testing and these two fields are initialized in constructor.
我正在测试的类中有两个私有字段，这两个字段在构造函数中初始化。
Now when I am trying to call using my class annotated with @InjectMocks, it is throwing exception:
现在，当我尝试使用用@InjectMocks 注释的类进行调用时，它抛出异常：
Cannot instantiate @InjectMocks field named 'ServiceImpl' of type 'class com.test.ServiceImpl'. You haven't provided the instance at field declaration so I tried to construct the instance.
Below is the piece of code.
下面是一段代码。
public class ServiceImpl implements Service {
private OfficeDAO officeDAO ;
private DBDAO dbDAO ;
public ServiceImpl() {
officeDAO = Client.getDaoFactory().getOfficeDAO();
dbDAO = Client.getDaoFactory().getDBDAO();
}
My test class:
我的测试班：
@RunWith(MockitoJUnitRunner.class)
public class ServiceImplTest {
@Mock
private OfficeDAO officeDAO;
@Mock
private DBDAO dbDAO;
@Mock
Client client;
@InjectMocks
private ServiceImpl serviceImpl;
@Mock
private Logger log;
@Before
public void setUp() throws Exception {
MockitoAnnotations.initMocks(this);
}
Please help me how I can resolve it. Any help will be appreciated.
请帮助我如何解决它。任何帮助将不胜感激。
回答by bbankowski
You are using @InjectMocksannotation, which creates an instance of ServiceImplclass. Because your constructor is trying to get implementation from factory: Client.getDaoFactory().getOfficeDAO()you have NPE.
您正在使用@InjectMocks注释，它创建ServiceImpl类的实例。因为您的构造函数正试图从工厂获得实现：Client.getDaoFactory().getOfficeDAO()您有 NPE。
Make sure what is returned by Client.getDaoFactory(). I bet it returns null and that's the problem :) Refactor your code, so that DaoFactory is passed via parameter rather than using static.
确保Client.getDaoFactory(). 我敢打赌它返回 null，这就是问题所在:) 重构您的代码，以便 DaoFactory 通过参数而不是使用静态传递。
I see you have a different exception right now. But based on the code I cannot really tell more. Please, provide full example of failing test.
我看到你现在有一个不同的例外。但根据代码，我真的不能说更多。请提供失败测试的完整示例。
