java线程池

public class Main {

    public static void main(String[] args) throws Exception {

        // 有界队列（当创建的线程超出了最大线程数，就会到队列中进行等待。）
       // 当创建的线程数 > 线程池的最大线程数 + 队列的数量  的时候多余的线程将会被拒绝（线程就不会再创建了）
        BlockingQueue<Runnable> workQueue = new ArrayBlockingQueue<>(9);
        // 放弃拒绝的任务并抛出异常(拒绝策略)
        RejectedExecutionHandler abortPolicyHandler = new ThreadPoolExecutor.AbortPolicy();
        // 放弃拒绝任务抛出异常 （拒绝策略）
        RejectedExecutionHandler discardPolicyHandler = new hreadPoolExecutor.DiscardPolicy();
       // 这里的线程池最终会拒绝一个线程
        ThreadPoolExecutor threadPool = 
         new ThreadPoolExecutor(2, 5, 6, TimeUnit.SECONDS, workQueue, discardPolicyHandler);
        long start = System.currentTimeMillis();
        for (int i = 0; i < 15; i++) {
            MyTask myTask = new MyTask();
            threadPool.execute(myTask);
            System.out.println("核心线程数" + threadPool.getCorePoolSize());
            System.out.println("最大线程数" + threadPool.getMaximumPoolSize());
            System.out.println("线程池数" + threadPool.getPoolSize());
            System.out.println("队列任务数" + threadPool.getQueue().size());
            System.out.println(">>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>" + i);
        }

        System.out.println(System.currentTimeMillis()-start);
        threadPool.shutdown();
        if (threadPool.awaitTermination(6, TimeUnit.SECONDS)) {
            threadPool.shutdownNow();
        }
    }
}
// 创建线程
class MyTask implements Runnable {
    public void run() {
        try {
            Thread.currentThread().sleep(5000);
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        System.out.println(Thread.currentThread().getName() + ", hello");
    }
}