单元测试中断异常 ThreadPoolTaskExecutor with Mockito Spy.

Question

我正在使用 spring 的ThreadPoolTaskExecutor在多个线程中执行任务。类如下所示

@Component
public class LoadData {
//... ...    
@Inject
private ThreadPoolTaskExecutor taskExecutor;
public SomeData getData(Long id) {
Future<SomeData> loadData = taskExecutor.submit(() -> {
//return methodToGetDataSynchronously(id);
return new SomeData();
});
try {
SomeData data = loadData.get();
} catch (InterruptedException | ExecutionException e) {
logger.error("error");
//some more processing for the error here
}
return data;
}
}

为了能够对此类进行单元测试并涵盖InterruptedException和ExecutionException分支，我尝试了多种方法(使用MockitoSpy(，但未能成功测试。

单元测试类如下所示：

@RunWith(MockitoJUnitRunner.class)
public class LoadDataTest {
@InjectMocks
private LoadData loadData;
@Spy
private ThreadPoolTaskExecutor spyTaskExecutor = new ThreadPoolTaskExecutor();
@Before
public void init() {
MockitoAnnotations.initMocks(this);
spyTaskExecutor.setCorePoolSize(1);
spyTaskExecutor.setWaitForTasksToCompleteOnShutdown(true);
spyTaskExecutor.initialize();
}
@Test
public void testGetData_shouldThrowInterruptedException () {
Mockito.when(spyTaskExecutor.submit(Matchers.<Callable<SomeData>>any())).thenAnswer(new Answer<Future<SomeData>>() {
public Future<SomeData> answer(InvocationOnMock invocation) throws Throwable {
Future<SomeData> future = Mockito.mock(FutureTask.class);
when(future.isDone()).thenReturn(false, false, true);
when(future.get()).thenThrow(new InterruptedException ());
return future;
}
});
SomeData result = null;
result = loadData.getData(101L);
//verify here that InterruptedException processing was performed
}
}

我正在使用Spy进行ThreadPoolTaskExecutor，因为我在测试中还有其他方法可以测试多线程执行的实际行为。 当我尝试运行测试方法时，它会NullPointerException存根间谍：

Mockito.when(spyTaskExecutor.submit(Matchers.<Callable<SomeData>>any()))...

例外情况：

java.lang.NullPointerException
at java.util.concurrent.AbstractExecutorService.submit(AbstractExecutorService.java:132)
at org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor.submit(ThreadPoolTaskExecutor.java:320)
at com.company.LoadDataTest.testGetData_shouldThrowInterruptedException(LoadDataTest.java:20)

我想，问题可能出在我刺杀莫基托间谍的方式上。但是，我不确定我是否走在正确的道路上，以存根InterruptedException.有没有人有过如何实现这一目标的样本？

版本：

jdk-1.8.0_72
junit-4.12
mockito-core-1.10.19
spring-context-4.3.4.RELEASE

注意：这是实际代码的摘录。实际代码执行许多其他操作，并将许多其他 bean 注入其中 - 其中一些在Test中Mock，有些是Spy的 - 具体取决于我正在测试的内容。我只提到了我在这里面临问题的部分。

Answer 1

终于想通了问题。我真的很接近，只是Mockito Spy的使用有点不对劲。这是工作解决方案：

@RunWith(MockitoJUnitRunner.class)
public class LoadDataTest {
@InjectMocks
private LoadData loadData;
@Spy
private ThreadPoolTaskExecutor spyTaskExecutor = new ThreadPoolTaskExecutor();
@Before
public void init() {
MockitoAnnotations.initMocks(this);
spyTaskExecutor.setCorePoolSize(1);
spyTaskExecutor.setWaitForTasksToCompleteOnShutdown(true);
spyTaskExecutor.initialize();
}
@Test
public void testGetData_shouldThrowInterruptedException () {
setupSpyTaskExecutorForException(new InterruptedException("junit"));
SomeData result = loadData.getData(101L);
//verify here that InterruptedException processing was performed
}
private void setupSpyTaskExecutorForException(Exception e) {
Mockito.doAnswer(new Answer<Future<?>>() {
public Future<?> answer(InvocationOnMock invocation) throws Throwable {
Future<?> future = Mockito.mock(FutureTask.class);
when(future.get()).thenThrow(e);
return future;
}
}).when(spyTaskExecutor).submit(Matchers.<Callable<?>>any());
}
}