我有一些代码
service.doAction(request, Callback<Response> callback);
我如何使用Mockito抓取回调对象,并调用callback.reply(x)
答案 0 :(得分:68)
您想要设置一个Answer
对象来执行此操作。看看Mockito文档,在
https://static.javadoc.io/org.mockito/mockito-core/2.8.47/org/mockito/Mockito.html#answer_stubs
您可能会写一些类似
的内容when(mockService.doAction(any(Request.class), any(Callback.class))).thenAnswer(
new Answer<Object>() {
Object answer(InvocationOnMock invocation) {
((Callback<Response>) invocation.getArguments()[1]).reply(x);
return null;
}
});
(当然应该用它应该的任何东西替换x
)
答案 1 :(得分:45)
考虑使用ArgumentCaptor,它在任何情况下都更接近于“抓住[bing]回调对象”。
/**
* Captor for Response callbacks. Populated by MockitoAnnotations.initMocks().
* You can also use ArgumentCaptor.forClass(Callback.class) but you'd have to
* cast it due to the type parameter.
*/
@Captor ArgumentCaptor<Callback<Response>> callbackCaptor;
@Test public void testDoAction() {
// Cause service.doAction to be called
// Now call callback. ArgumentCaptor.capture() works like a matcher.
verify(service).doAction(eq(request), callbackCaptor.capture());
assertTrue(/* some assertion about the state before the callback is called */);
// Once you're satisfied, trigger the reply on callbackCaptor.getValue().
callbackCaptor.getValue().reply(x);
assertTrue(/* some assertion about the state after the callback is called */);
}
当回调需要立即返回时(读取:同步),Answer
是一个好主意,它还会引入创建匿名内部类的开销,并且不安全地从invocation.getArguments()[n]
转换元素到你想要的数据类型。它还要求您从Answer中包含有关系统预回调状态的任何断言,这意味着您的答案的大小和范围可能会增大。
相反,异步处理回调:使用ArgumentCaptor捕获传递给服务的Callback对象。现在,您可以在测试方法级别进行所有断言,并在选择时调用reply
。如果您的服务负责多个同时回调,则此功能特别有用,因为您可以更好地控制回调返回的顺序。
答案 2 :(得分:4)
如果您有类似以下方法:-
public void registerListener(final IListener listener) {
container.registerListener(new IListener() {
@Override
public void beforeCompletion() {
}
@Override
public void afterCompletion(boolean succeeded) {
listener.afterCompletion(succeeded);
}
});
}
然后通过以下方式可以轻松模拟上述方法:-
@Mock private IListener listener;
@Test
public void test_registerListener() {
target.registerListener(listener);
ArgumentCaptor<IListener> listenerCaptor =
ArgumentCaptor.forClass(IListener.class);
verify(container).registerListener(listenerCaptor.capture());
listenerCaptor.getValue().afterCompletion(true);
verify(listener).afterCompletion(true);
}
我希望这对某人有帮助,因为我花了很多时间来找出解决方案
答案 3 :(得分:2)
when(service.doAction(any(Request.class), any(Callback.class))).thenAnswer(
new Answer() {
Object answer(InvocationOnMock invocation) {
Callback<Response> callback =
(Callback<Response>) invocation.getArguments()[1];
callback.reply(/*response*/);
}
});