Mocked ExecutorService始终返回相同的模拟未来

Question

我实现了一个模拟ExecutorService来立即返回结果，而无需创建线程：

public static ExecutorService createMock() throws Exception {
    ExecutorService executorServiceMock = EasyMock.createMock(ExecutorService.class);
    Future future = EasyMock.createMock(Future.class);
    Capture<Callable<?>> callableCapture = new Capture<>();
            EasyMock.expect(executorServiceMock.submit(EasyMock.<Callable<?>>capture(callableCapture))).andReturn(future).anyTimes();
    EasyMock.expect(future.get()).andAnswer(() -> callableCapture.getValue().call()).anyTimes();

    executorServiceMock.shutdown();
    EasyMock.expectLastCall().anyTimes();
    EasyMock.replay(future, executorServiceMock);
    return executorServiceMock;
}

问题是它总是返回相同的[mocked]Future对象。我需要根据传递给执行器的可调用对象返回Future mock的新实例ServiceMock.submit（）我尝试使用PowerMock.expectNew（Future.class），但它抱怨“在类'java.util.concurrent.Future'中找不到带有参数类型的构造函数：[]”

Answer 1

下面的代码修复了我的问题。

@Mock
private ThreadPoolExecutor executorPool;

Future<String> result = CompletableFuture.completedFuture("S3PATH");
when(executorPool.submit(Mockito.<Callable<String>> anyObject())).thenReturn(result);

Answer 2

捕获将始终返回上次捕获的对象。在您的情况下，您似乎希望同步提交和获取。

因此，我认为你应该做以下几点：

    ExecutorService executorServiceMock = createMock(ExecutorService.class);

    expect(executorServiceMock.submit(EasyMock.<Callable<?>>anyObject()))
        .andAnswer(() -> {
            Future future = createMock(Future.class);
            Object value = ((Callable<?>) getCurrentArguments()[0]).call();
            expect(future.get()).andReturn(value);
            replay(future);
            return future;
        })
        .anyTimes();

    executorServiceMock.shutdown();
    expectLastCall().anyTimes();

    replay(executorServiceMock);

    return executorServiceMock;

Answer 3

首先，“不要模仿你没有的类型！”。通过链接，您可能会找到几个不应该这样做的原因。

但是，如果您真的想这样做，那么通过应答替换返回模拟每次都会创建一个新的nock：

EasyMock.expect(executorServiceMock.submit(EasyMock.<Callable<?>>capture(callableCapture))).andAnswer(() -> {
    Future future = EasyMock.createMock(Future.class);
    EasyMock.expect(future.get()).andAnswer(() -> callableCapture.getValue().call()).anyTimes();
    EasyMock.replay(future);
    return future;
}).anyTimes();

顺便说一下，您不能期望PowerMock.expectNew（Future.class），因为Future是接口，无法创建。