diff --git a/core-java-8/src/test/java/com/baeldung/java8/Java8ExecutorServiceTest.java b/core-java-8/src/test/java/com/baeldung/java8/Java8ExecutorServiceTest.java new file mode 100644 index 0000000000..1609ae98a4 --- /dev/null +++ b/core-java-8/src/test/java/com/baeldung/java8/Java8ExecutorServiceTest.java @@ -0,0 +1,155 @@ +package com.baeldung.java8; + + +import org.junit.Before; +import org.junit.Test; + +import java.util.ArrayList; +import java.util.List; +import java.util.concurrent.*; +import static org.junit.Assert.*; + + +public class Java8ExecutorServiceTest { + + private Runnable runnableTask; + private Callable callableTask; + private List> callableTasks; + + @Before + public void init() { + + runnableTask = () -> { + try { + TimeUnit.MILLISECONDS.sleep(300); + } catch (InterruptedException e) { + e.printStackTrace(); + } + }; + + callableTask = () -> { + TimeUnit.MILLISECONDS.sleep(300); + return "Task's execution"; + }; + + callableTasks = new ArrayList<>(); + callableTasks.add(callableTask); + callableTasks.add(callableTask); + callableTasks.add(callableTask); + } + + @Test + public void creationSubmittingTaskShuttingDown_whenShutDown_thenCorrect() { + + ExecutorService executorService = Executors.newFixedThreadPool(10); + executorService.submit(runnableTask); + executorService.submit(callableTask); + executorService.shutdown(); + + assertTrue(executorService.isShutdown()); + } + + @Test + public void creationSubmittingTasksShuttingDownNow_whenShutDownAfterAwating_thenCorrect() { + + ExecutorService threadPoolExecutor = + new ThreadPoolExecutor(1, 1, 0L, TimeUnit.MILLISECONDS, + new LinkedBlockingQueue<>()); + + for (int i = 0; i < 100; i++) { + threadPoolExecutor.submit(callableTask); + } + + List notExecutedTasks = smartShutdown(threadPoolExecutor); + + assertTrue(threadPoolExecutor.isShutdown()); + assertFalse(notExecutedTasks.isEmpty()); + assertTrue(notExecutedTasks.size() > 0 && notExecutedTasks.size() < 98); + } + + private List smartShutdown(ExecutorService executorService) { + + List notExecutedTasks = new ArrayList<>(); + executorService.shutdown(); + try { + if (!executorService.awaitTermination(800, TimeUnit.MILLISECONDS)) { + notExecutedTasks = executorService.shutdownNow(); + } + } catch (InterruptedException e) { + notExecutedTasks = executorService.shutdownNow(); + } + return notExecutedTasks; + } + + @Test + public void submittingTasks_whenExecutedOneAndAll_thenCorrect() { + + ExecutorService executorService = Executors.newFixedThreadPool(10); + + String result = null; + List> futures = new ArrayList<>(); + try { + result = executorService.invokeAny(callableTasks); + futures = executorService.invokeAll(callableTasks); + } catch (InterruptedException | ExecutionException e) { + e.printStackTrace(); + } + + assertEquals("Task's execution", result); + assertTrue(futures.size() == 3); + } + + @Test + public void submittingTaskShuttingDown_whenGetExpectedResult_thenCorrect() { + + ExecutorService executorService = Executors.newFixedThreadPool(10); + + Future future = executorService.submit(callableTask); + String result = null; + try { + result = future.get(); + result = future.get(200, TimeUnit.MILLISECONDS); + } catch (InterruptedException | ExecutionException | TimeoutException e) { + e.printStackTrace(); + } + + executorService.shutdown(); + + assertEquals("Task's execution", result); + } + + @Test + public void submittingTask_whenCanceled_thenCorrect() { + + ExecutorService executorService = Executors.newFixedThreadPool(10); + + Future future = executorService.submit(callableTask); + + boolean canceled = future.cancel(true); + boolean isCancelled = future.isCancelled(); + + executorService.shutdown(); + + assertTrue(canceled); + assertTrue(isCancelled); + } + + @Test + public void submittingTaskScheduling_whenExecuted_thenCorrect() { + + ScheduledExecutorService executorService = Executors + .newSingleThreadScheduledExecutor(); + + Future resultFuture = executorService.schedule(callableTask, 1, TimeUnit.SECONDS); + String result = null; + try { + result = resultFuture.get(); + } catch (InterruptedException | ExecutionException e) { + e.printStackTrace(); + } + + executorService.shutdown(); + + assertEquals("Task's execution", result); + } +}