java模拟自定义对象

public class MainClass  {

    public void makeCall() {
        CustomObject obj = new CustomObject();
        obj.testMethod();
    }
}

我想进行单元测试makeCall()。所以我必须嘲笑CustomObject在上面的示例中。我使用 Mockito 作为模拟框架。但是当我像这样模拟对象时mock(CustomObject.class). makeCall()方法总是调用实际对象而不是模拟对象。无论如何，有没有模拟本地对象。请帮忙

单元测试友好的版本MainClass应该有CustomObject注入，例如：

public class MainClass  {
    private CustomObject customObject = new CustomObject();  // a default one if none is provided

    public void setCustomObject(CustomObject customObject) {
        this.customObject = customObject;
    }

    public void makeCall() {
        this.customObject.testMethod();
    }
}

你的测试将如下所示：

CustomObject mockCustomObject = mock(CustomObject.class);
when(mockCustomObject.testMethod()).thenReturn(...);

MainClass sut = new MainClass();
sut.setCustomObject(mockCustomObject);

sut.makeCall();

verify(mockCustomObject).testMethod();

有了Mockito的注解，可以进一步简化为：

public class MyClassTest {
    @InjectMocks
    private MainClass mainClass;

    @Mock
    private CustomObject mockCustomObject;

    @Before
    public void setup() {
        MockitoAnnotations.initMocks(this);  // or use mockito runner
    }

    @Test
    public void testMakeCall() {
        when(mockCustomObject.testMethod()).thenReturn(...);
        mainClass.makeCall();
        verify(mockCustomObject).testMethod();
    }
}