Java教程：如何使用异步多线程处理业务并优雅关闭

正文：

版本一：

public void manyThread() {
    List list = Arrays.asList("1", "2", "3");
    // 计数器
    CountDownLatch downLatch = new CountDownLatch(list.size());
    // 创建线程
    ExecutorService executorService = null;
    try {
        executorService = Executors.newFixedThreadPool(list.size());
        for (String item : list) {
            // 开启线程
            executorService.execute(() -> {
                try {
                    // 业务处理
                    System.out.println(item);
                } finally {
                    downLatch.countDown();
                }
            });
        }
        downLatch.await();
    } catch (InterruptedException e) {
        throw new RuntimeException(e);
    } finally {
        if (executorService != null) {
            executorService.shutdown();
        }
    }
}