Java 使用 Mockito 模拟界面
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Mocking an interface with Mockito
提问by Mike
Can someone please help me with the below Mock object. I want to write a mock test case for ServiceImpl class. I want to mock OrderIF interface:
有人可以帮我处理下面的 Mock 对象吗？我想为 ServiceImpl 类编写一个模拟测试用例。我想模拟 OrderIF 接口：
public interface OrderIF{
List<Order> ordersFor(String type);
}
The implementation of service is:
服务的实现是：
public class ServiceImpl implements Service {
private List <Order> orders ;
private OrderIF orderif ; // this is 3rd party interface
public int getval(String type) {
//some code
// this returns a list of objects (orders)
orders = orderif.ordersFor(type);
// some code
return orders.get(0)
}
}
My code give NullPoinerException:
我的代码给出 NullPoinerException：
public class ServiceImplTest {
private List <Order> ll ;
private service reqService ;
@InjectMocks
private orderIF order;
@Before
public void setUp() throws Exception {
ll = new ArrayList<Order> ();
ll.add(new Order("Buy" , 11 , "USD" ));
ll.add(new Order("Sell" , 22 , "USD" ));
reqService = spy(new ServiceImpl());
}
@Test
public void test() {
String type= "USD" ;
when(order.ordersFor(type)).thenReturn(ll);
q = reqService.getval(type);
assertTrue(q.get().ask == 232.75);
}
}
回答by Jonathan
I'm guessing that orderis nulland you're getting the NullPointerExceptionhere:
我猜order是这样null，你会得到NullPointerException这里：
when(order.ordersFor(type)).thenReturn(ll);
For @InjectMocksto work and instantiate your class, you'll need to add a runner:
为了@InjectMocks工作和实例化你的类，你需要添加一个跑步者：
@RunWith(MockitoJUnitRunner.class)
public class ServiceImplTest {
// ...
}
You don't have to use the runner, refer to the documentationfor alternatives.
您不必使用转轮，请参阅文档以获取替代方案。
回答by Sergii Bishyr
@InjectMockswill not instantiate or mock your class. This annotation is used for injecting mocks into this field.
@InjectMocks不会实例化或模拟您的类。此注释用于将模拟注入此字段。
If you want to test serviceImplyou will need to mock in this way:
如果你想测试，serviceImpl你需要以这种方式模拟：
@Mock
private OrderIF order;
@InjectMocks
private Service reqService = new ServiceImpl();
To make it work you either need to use runner or MockitoAnnotations.initMocks(this);in @Beforemethod.
要使其工作，您需要使用 runner 或MockitoAnnotations.initMocks(this);in@Before方法。
