我需要使用countdownlatch进行以下代码的单元测试。这只是一个测试代码。我使用mockito thenAnswer和InvocationOnMask来模拟线程/可调用。但我不知道如何在单元测试中初始化/模拟或退出countdownlatch。
public class ThreadPoolTaskExecRunner {
private ThreadPoolTaskExecutor threadPoolTaskExecutor = new ThreadPoolTaskExecutor();
private ArrayBlockingQueue<String> values = new ArrayBlockingQueue<String>(100, true);
public ThreadPoolTaskExecRunner() {
threadPoolTaskExecutor.setCorePoolSize(5);
threadPoolTaskExecutor.setMaxPoolSize(10);
threadPoolTaskExecutor.setWaitForTasksToCompleteOnShutdown(true);
threadPoolTaskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
threadPoolTaskExecutor.initialize();
}
public static void main(String args[]) {
ThreadPoolTaskExecRunner obj = new ThreadPoolTaskExecRunner();
obj.testCountDownLatch();
}
public void testCountDownLatch() {
final CountDownLatch latch = new CountDownLatch(5);
Future<String> future1 = threadPoolTaskExecutor.submit(new Task("A", values, latch));
Future<String> future3 = threadPoolTaskExecutor.submit(new Task("B", values, latch));
Future<String> future4 = threadPoolTaskExecutor.submit(new Task("C", values, latch));
Future<String> future5 = threadPoolTaskExecutor.submit(new Task("D", values, latch));
Future<String> future2 = threadPoolTaskExecutor.submit(new Task("E", values, latch));
try{
latch.await(); //main thread is waiting on CountDownLatch to finish
}catch(InterruptedException ie){
System.out.println(ie);
}
System.out.println("*********** DONE *********** values size= "+values.size());
for(String s : values)
System.out.println(s);
threadPoolTaskExecutor.shutdown();
}
public static class Task implements Callable<String> {
private String type;
private ArrayBlockingQueue<String> values;
private CountDownLatch latch;
public Task(String s, ArrayBlockingQueue<String> values, CountDownLatch latch) {
this.type = s;
this.values = values;
this.latch = latch;
}
@Override
public String call() throws Exception {
try {
System.out.println("Inside call type: " + type);
Thread.sleep(10);
values.add(type);
return type;
} finally {
if(latch != null)
latch.countDown();
}
}
}
}
我开发了单元测试类,但它没有用......
@RunWith(MockitoJUnitRunner.class)
public class ThreadPoolTaskExecRunnerTest {
@Mock
private ThreadPoolTaskExecutor taskExecutor;
@InjectMocks
ThreadPoolTaskExecRunner threadPoolTaskExecRunner;
@Test
public void test() {
when(taskExecutor.submit(any(ThreadPoolTaskExecRunner.Task.class))).thenAnswer(new Answer<Future<String>>() {
public Future<String> answer(InvocationOnMock invocation) throws Throwable {
Future<String> future = mock(FutureTask.class);
when(future.isDone()).thenReturn(false, false, true);
when(future.get()).thenReturn("This is a test");
return future;
}
});
threadPoolTaskExecRunner.testCountDownLatch();
}
}
答案 0 :(得分:2)
那你想测试什么?我想你想测试countDown
被调用了。所以你可以这样做:
public void taskCallsCountDownOnce() {
// setup
final CountDownLatch latch = mock(CountDownLatch.class);
// execution
new Task("A", values, latch).call();
// evaluation
verify(latch).countDown();
}
如果您还想在调用countDown之前测试该值已添加,请使用:
public void taskAddsValueBeforeCallingCountDown() {
// setup & execution
// ...
// evaluation
InOrder inOrder = inOrder(latch, values);
inOrder.verify(values).add(...);
inOrder.verify(latch).countDown();
}
一般说明:
Future.get()
会更容易,这也会等到任务完成Task
那样处理并发问题。它不关心它是否在一个新的线程中执行,它恰好在你的情况下。所以你可以单独测试这个类。如果您很好地构建代码,那么您将拥有处理线程组织的类,而不会执行任何其他类以及执行工作的其他类。这使得分离算法测试和线程处理测试更容易,并且测试更容易阅读。