DelayQueue解决java中延时提醒

// 用于控制并发的锁

private final transient ReentrantLock lock = new ReentrantLock();

// 优先级队列

private final PriorityQueue<E> q = new PriorityQueue<E>();

// 用于标记当前是否有线程在排队（仅用于取元素时）

private Thread leader = null;

// 条件，用于表示现在是否有可取的元素

private final Condition available = lock.newCondition();

public class Tt {

    private DelayQueue<OrderInfo> messageQueue = new DelayQueue<OrderInfo>(); //消息队列

    public static void main(String[] args) {

        Tt t = new Tt();

        OrderInfo oi = new OrderInfo("1", new Date().getTime() + 3000); // 加3000，表示延时3秒

        OrderInfo oi2 = new OrderInfo("2", new Date().getTime() + 3000);

        t.messageQueue.offer(oi); // 当接收到订单后，往队列里放一条消息

        t.messageQueue.offer(oi2);

        System.out.println(new Date().toString() + "启动，并加入了两条消息"); // 模拟接收到了两个订单

        // 这里是消费线程，随程序运行启动

        t.handle();

    }

    private void handle() {

        ThreadPoolHolder.getThreadPool().submit(new Runnable() {

            @Override

            public void run() {

                while (true) {

                    try {

                        OrderInfo message = messageQueue.take(); // take方法，有消息（延时时间<0的消息）取消息，没有，阻塞住。

                        // 这里查一遍订单.. 符合需求发消息，不符合不发

                        System.out.println(new Date().toString() + " ..... 发送消息id " + message.getId());

                    } catch (InterruptedException e) {

                        e.printStackTrace();

                    }

                }

            }

        });

    }

}

// 消息体，必须实现Delayed接口

public class OrderInfo implements Delayed {

    private String id;

    public OrderInfo(String id, long excuteTime) {

        this.id = id;

        this.excuteTime = excuteTime;

    }

    private long excuteTime;// 延迟时长，这个是必须的属性因为要按照这个判断延时时长。

    public String getId() {

        return id;

    }

    @Override

    public long getDelay(TimeUnit unit) {

        return unit.convert(excuteTime,TimeUnit.NANOSECONDS) - unit.convert(System.currentTimeMillis(),TimeUnit.NANOSECONDS);

    }

    @Override

    public int compareTo(Delayed o) {

        OrderInfo msg = (OrderInfo) o;

        return Integer.valueOf(this.id) > Integer.valueOf(msg.id) ? 1

                : (Integer.valueOf(this.id) < Integer.valueOf(msg.id) ? -1 : 0);

    }

}