模拟执行器服务总是返回相同的模拟未来

Question

我实现了一个模拟的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 [模拟] Future 对象。我需要根据传递给 executorServiceMock.submit（） 的可调用对象返回 Future mock 的新实例我尝试使用PowerMock.expectNew（Future.class），但它抱怨"在类'java.util.concurrent.Future'中找不到参数类型为[ ]的构造函数"

Answer 1

首先是"不要嘲笑你不拥有的类型！通过链接，您可能会找到几个不应该这样做的原因。

但是，如果你真的想这样做，那么通过答案女巫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) Future因为这是接口，无法创建。

Answer 2

捕获将始终返回最后一个捕获的对象。在您的情况下，您似乎想要同步提交和获取。

所以，我认为你应该做到以下几点：

    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

下面的代码解决了我的问题。

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