getAnnotation（<T>類）總是當我使用了EasyMock/PowerMock嘲笑java.lang.reflect.Method中

Question

的測試方法具有以下代碼返回null java.lang.reflect.Method中：

Method method= PowerMock.createMock(Method.class); 
SuppressWarnings sw = EasyMock.createMock(SuppressWarnings.class); 
EasyMock.expect(method.getAnnotation(SuppressWarnings.class)).andReturn(sw); 

在被測試的方法，
method.getAnnotation（SuppressWarnings.class）;總是返回null。

我不知道爲什麼。有人能幫助我嗎？

//code: 
@Retention(RetentionPolicy.RUNTIME) 
@Target(ElementType.METHOD) 
public @interface Anonymous { 

} 

public class AnnotationClass { 
    public Anonymous fun(Method m){ 
     Anonymous anonymous = m.getAnnotation(Anonymous.class); 
     return anonymous; 
    } 
} 

// test class: 
@RunWith(PowerMockRunner.class) 
@PrepareForTest(Method.class) 
public class AnnotationClassTest { 
    @Test 
    public void test() throws NoSuchMethodException, SecurityException { 
     AnnotationClass testClass = new AnnotationClass(); 
     final Method mockMethod = PowerMock.createMock(Method.class); 
     final Anonymous mockAnot = EasyMock.createMock(Anonymous.class); 

     EasyMock.expect(mockMethod.getAnnotation(Anonymous.class)).andReturn(mockAnot); 
     PowerMock.replay(mockMethod); 

     final Anonymous act = testClass.fun(mockMethod); 
     Assert.assertEquals(mockAnot, act); 

     PowerMock.verify(mockMethod); 
    } 
} 

error: 
java.lang.AssertionError: expected:<EasyMock for interface 
com.unittest.easymock.start.Anonymous> but was:<null> 

Answer 1

SuppressWarnings具有@Retention(value=SOURCE)這意味着它不提供在運行時：

public static final RetentionPolicy SOURCE：註釋是由編譯器被丟棄。

但是，如果你會用不同的註釋，在運行時可嘗試你的代碼，method.getAnnotation(MyAnnotation.class)仍然會返回null。也就是說，因爲默認情況下，模擬的Method將返回方法調用null。

我覺得你的問題是在模擬的配置，當我運行的代碼（使用一個註解，可在運行時）我得到以下異常：

Exception in thread "main" java.lang.IllegalStateException: no last call on a mock available 
at org.easymock.EasyMock.getControlForLastCall(EasyMock.java:466) 
at org.easymock.EasyMock.expect(EasyMock.java:444) 
at MockStuff.main(MockStuff.java:54) 

This page在如何一些解釋嘲笑最後一堂課（如Method）。

---

你的代碼給我完全一樣的結果。我能得到它的工作使用下面的代碼：

@RunWith(PowerMockRunner.class) 
@PrepareForTest(Method.class) 
public class AnnotationClassTest { 
    @Test 
    public void test() throws NoSuchMethodException, SecurityException { 
    final Method mockMethod = PowerMock.createMock(Method.class); 
    final Anot mockAnot = EasyMock.createMock(Anot.class); 

    EasyMock.expect(mockMethod.getAnnotation(Anot.class)).andReturn(mockAnot); 
    PowerMock.replay(mockMethod); 

    final Anot methodReturn = mockMethod.getAnnotation(Anot.class); 
    Assert.assertEquals(mockAnot, methodReturn); 
    } 
} 

@Retention(RetentionPolicy.RUNTIME) 
@interface Anot {} 

注意，這個代碼是自包含的，我定義的Anot接口，因爲你沒有給Anonymous定義。