Java 如何使用CountDownLatch对方法进行单元测试?
我需要做下面的代码,这是使用countdownlatch的单元测试。这只是一个测试代码。我使用mockito,然后使用answer和invocationmask来模拟线程/callable。但我不知道如何在单元测试中初始化/模拟或退出countdownlatchJava 如何使用CountDownLatch对方法进行单元测试?,java,unit-testing,countdownlatch,Java,Unit Testing,Countdownlatch,我需要做下面的代码,这是使用countdownlatch的单元测试。这只是一个测试代码。我使用mockito,然后使用answer和invocationmask来模拟线程/callable。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 ThreadPoolTask
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();
}
}
}
}
公共类ThreadPoolTaskExecRunner{
私有ThreadPoolTaskExecutor ThreadPoolTaskExecutor=新ThreadPoolTaskExecutor();
私有ArrayBlockingQueue值=新的ArrayBlockingQueue(100,true);
公共线程池TaskExecRunner(){
threadPoolTaskExecutor.setCorePoolSize(5);
threadPoolTaskExecutor.setMaxPoolSize(10);
threadPoolTaskExecutor.SetWaitForTaskStoCompleteonShutton(true);
threadPoolTaskExecutor.setRejectedExecutionHandler(新的ThreadPoolExecutor.CallerRunPolicy());
threadPoolTaskExecutor.initialize();
}
公共静态void main(字符串参数[]){
ThreadPoolTaskExecRunner obj=新的ThreadPoolTaskExecRunner();
obj.testCountDownLatch();
}
public void testCountDownLatch(){
最终倒计时闩锁=新倒计时闩锁(5);
Future future1=threadPoolTaskExecutor.submit(新任务(“A”,值,闩锁));
Future future3=threadPoolTaskExecutor.submit(新任务(“B”,值,闩锁));
Future future4=threadPoolTaskExecutor.submit(新任务(“C”,值,闩锁));
Future future5=threadPoolTaskExecutor.submit(新任务(“D”,值,闩锁));
Future future2=threadPoolTaskExecutor.submit(新任务(“E”,值,闩锁));
试一试{
latch.await();//主线程正在等待CountDownLatch完成
}捕获(中断异常ie){
系统输出打印(ie);
}
System.out.println(“***************完成************值大小=“+values.size()”);
用于(字符串s:值)
系统输出打印项次;
threadPoolTaskExecutor.shutdown();
}
公共静态类任务实现了可调用{
私有字符串类型;
私有ArrayBlockingQueue值;
私人倒计时闩锁;
公共任务(字符串s、ArrayBlockingQueue值、CountDownLatch闩锁){
this.type=s;
这个值=值;
this.latch=闩锁;
}
@凌驾
公共字符串调用()引发异常{
试一试{
System.out.println(“内部调用类型:“+type”);
睡眠(10);
值。添加(类型);
返回类型;
}最后{
如果(闩锁!=null)
倒计时();
}
}
}
}
我开发了单元测试类,但它没有帮助
@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();
}
}
@RunWith(MockitoJUnitRunner.class)
公共类ThreadPoolTaskExecuteRunnerTest{
@嘲弄
私有线程池taskExecutor taskExecutor;
@注射模拟
ThreadPoolTaskExecRunner ThreadPoolTaskExecRunner;
@试验
公开无效测试(){
当(taskExecutor.submit(any(ThreadPoolTaskExecRunner.Task.class))。然后回答(new-Answer(){
公共未来应答(invocationMock调用)抛出可丢弃的{
Future=mock(FutureTask.class);
when(future.isDone()).thenReturn(false,false,true);
when(future.get()).thenReturn(“这是一个测试”);
回归未来;
}
});
threadPoolTaskExecRunner.testCountDownLatch();
}
}
那么您想测试什么?我想您应该测试调用了countDown
。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();
}
如果您还想在调用倒计时之前测试该值是否已添加,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:
- 在这种特殊情况下,调用
会更容易,它也会等待任务完成Future.get()
- 给出测试方法的描述性名称,有助于理解测试内容
- 尽量使并发性远离单元测试。大多数类不像类
任务
那样处理并发性。它不在乎它是否在新线程中执行,它只是碰巧在您的情况下执行。所以你可以单独测试这个类。如果你能很好地构造你的代码,你将拥有处理线程组织的类,而不是其他的类,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,并且测试更易于阅读
- 那么你想测试什么?我想您应该测试调用了
countDown
。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();
}
如果您还想在调用倒计时之前测试该值是否已添加,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:
- 在这种特殊情况下,调用
会更容易,它也会等待任务完成Future.get()
- 给出测试方法的描述性名称,有助于理解测试内容
- 尽量使并发性远离单元测试。大多数类不像类
任务
那样处理并发性。它不在乎它是否在新线程中执行,它只是碰巧在您的情况下执行。所以你可以单独测试这个类。如果你能很好地构造你的代码,你将拥有处理线程组织的类,而不是其他的类,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,并且测试更易于阅读