多线程售票示例

业务介绍:

　　多线程执行春节车票售卖!

代码逻辑如下:

/**
 * 售票任务
 */
class TaskRunnable implements Runnable{

    /**
     * 剩余车票数量
     */
    private AtomicInteger count;

    /**
     * 当前任务名称
     */
    private String taskName;

    /**
     * 任务锁
     */
    private ReentrantLock lock;

    public TaskRunnable(AtomicInteger count, String taskName, ReentrantLock lock) {
        this.count = count;
        this.taskName = taskName;
        this.lock = lock;
    }

    @Override
    public void run() {
        System.out.println(taskName + "号售票厅的开始售票~~");
        while (true) {
            this.lock.lock();

            if (this.count.get() <= 0) {
                //任务结束解锁
                this.lock.unlock();
                break;
            }
            System.out.println("恭喜抢到" + taskName+"号销售厅的车票! 当前剩余车票数" + this.count.decrementAndGet());
            this.lock.unlock();
        }
        System.out.println(taskName+"号售票厅的售票结束--");
    }
}

/**
 * @author Kevin
 * @DateTime 2019/1/12 11:08
 * @Description
 */
public class ExecutorServiceL {

    public static void main(String[] args) {

        //创建线程池
        ExecutorService executorService = getExecutor();

        //执行任务
        executeTask(executorService);

        while (true) {
            if (((ThreadPoolExecutor) executorService).getActiveCount() <= 0) {
                System.out.println("售票结束~~");
                break;
            }
        }
        try {
            /**
             * 关闭线程池:
             * 1.不在接收新的任务
             * 2.等待已执行任务执行完毕
             * 3.关闭线程池(清除尚未执行任务,试图停止正在执行的任务)
             */
            executorService.shutdown();
            if (!executorService.awaitTermination(2, TimeUnit.SECONDS)) {
                System.out.println("尚未执行任务列表: "+executorService.shutdownNow());
            }

        } catch (Exception e) {
            System.out.println("超出时间强制结束!");
        }
    }

    /**
     * 执行任务
     *
     * @param executorService
     */
    public static void executeTask(ExecutorService executorService) {

        //总车票数
        AtomicInteger total = new AtomicInteger(30);
        //线程锁
        ReentrantLock lock = new ReentrantLock();

        executorService.execute(new TaskRunnable(total, "1", lock));
        executorService.execute(new TaskRunnable(total, "2", lock));
        executorService.execute(new TaskRunnable(total, "3", lock));
        executorService.execute(new TaskRunnable(total, "4", lock));
    }

    /**
     * 获取线程池
     *
     * @return
     */
    public static ExecutorService getExecutor() {
        return new ThreadPoolExecutor(
                2,
                4,
                2,
                TimeUnit.SECONDS,
                new SynchronousQueue(),
                new ThreadPoolExecutor.DiscardOldestPolicy()
        );
    }
}