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Accepted
Pavel Zlotarenchuk
Asked:2020-03-29 04:06:50 +0000 UTC2020-03-29 04:06:50 +0000 UTC

如何知道 ExecutorService 线程池是否已经完成？

  • 772

再会。有一个代码：

ExecutorService executorService = Executors.newFixedThreadPool(3);
        for (int i = 0; i < 3; i++) {
            executorService.execute(new ParallelRunnable(parallelGraph, parallelLineData, i));
    }

它创建一个线程池。问题是：如何捕获这个执行器的所有线程的完成并在完成时执行代码。动作发生在 android 上。

java

1 个回答

  1. Best Answer

    最笨拙的方法是等待池停止：

    ExecutorService executorService = Executors.newFixedThreadPool(3);
for (int i = 0; i < 3; i++) {
    executorService.execute(new ParallelRunnable(parallelGraph, parallelLineData, i));
}
taskExecutor.shutdown();
try {
    taskExecutor.awaitTermination(Long.MAX_VALUE, TimeUnit.NANOSECONDS);
    // Здесь выполнить действие
} catch (InterruptedException e) {
    ...
}

    更聪明的方法是在任务本身内协调工作的完成：

    CountDownLatch latch = new CountDownLatch(3);
for (int i = 0; i < 3; i++) {
    executorService.execute(() -> {
        try {
            // Выполнение задачи
            latch.countDown();
        } catch (InterruptedException e) {
            Thread.currentThread().interrupt();
        }
    });
}
latch.await();
// Здесь выполнить действие

    在我看来，最明智的做法是使用 CompletableFuture：

    ComplatableFuture<Void>[] futures = new ComplatableFuture<>[3];
for (int i = 0; i < 3; i++) {
    futures[i] = CompletableFuture.runAsync(new ParallelRunnable(parallelGraph, parallelLineData, i), executorService);
}
CompletableFuture.allOf(futures)
                 .thenRun(() -> {
                     // Здесь выполнить действие
                 });
    • 5

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