JUC并發編程-生產者消費者實體

生產者消費者實體

1.ReentrantLock實作

public class Demo {
    public static void main(String[] args) {
        Data data=new Data();

        //兩個生產者執行緒
        for (int i = 0; i < 2; i++) {
            new Thread(()->{
                try {
                    data.increment();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            },"生產者"+String.valueOf(i)).start();
        }

        //兩個消費者執行緒
        for (int i = 2; i < 4; i++) {
            new Thread(()->{
                try {
                    data.decrement();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            },"消費者"+String.valueOf(i)).start();
        }
    }
}

class Data{
    //共享資源
    private int number=0;


    Lock lock=new ReentrantLock();

    Condition condition= lock.newCondition();

    public void increment() throws InterruptedException {
        //上鎖
        lock.lock();

        try {
            //回圈判斷條件，不用if避免虛假喚醒
            while (number!=0){
                //不滿足條件就等待
                condition.await();
            }
            //操作 生產
            number++;
            System.out.println(Thread.currentThread().getName()+"執行緒\t"+number);
            //通知喚醒等待的消費者執行緒
            condition.signalAll();

        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        //解鎖
        lock.unlock();
    }


    public void decrement() throws InterruptedException {
        //上鎖
        lock.lock();

        try {
            while (number==0){
                condition.await();
            }

            number--;
            System.out.println(Thread.currentThread().getName()+"執行緒\t"+number);
            condition.signalAll();

        } catch (InterruptedException e) {
            e.printStackTrace();
        }


        lock.unlock();
    }
}

2.阻塞佇列實作

public class 阻塞佇列版 {
    public static void main(String[] args) {
            MyResource myResource=new MyResource(new ArrayBlockingQueue(10));

            new Thread(()->{
                System.out.println("生產執行緒啟動");
                try {
                    myResource.myProd();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            },"Prod").start();

            new Thread(()->{
                System.out.println("消費執行緒啟動");
                try {
                    myResource.myConsumer();
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            },"Consumer").start();

        try {
            Thread.sleep(5000);
            System.out.println();
            System.out.println();
            System.out.println();
            System.out.println();

            myResource.stop();
            System.out.println("5秒時間到，老板main執行緒叫停");
        } catch (InterruptedException e) {
        }
    }
}

class MyResource{

    //默認開啟，開始生產消費
    private volatile boolean FLAG=true;

    private AtomicInteger atomicInteger=new AtomicInteger();

    BlockingQueue<String> blockingQueue=null;

    public MyResource(BlockingQueue blockingQueue1){
        blockingQueue=blockingQueue1;
        System.out.println(blockingQueue1.getClass().getName());
    }

    //生產方法
    public void myProd() throws InterruptedException {
        String data=null;
        boolean result;

        while (FLAG){

           data=atomicInteger.incrementAndGet()+"";
           result=blockingQueue.offer(data,2L, TimeUnit.SECONDS);
           if(result){
               System.out.println(Thread.currentThread().getName()+"\t 插入佇列"+data+"成功");
           }else{
               System.out.println(Thread.currentThread().getName()+"\t 插入佇列"+data+"失敗");
           }
           TimeUnit.SECONDS.sleep(1);
        }
        System.out.println("生產結束");

    }

    //消費方法
    public void myConsumer() throws InterruptedException {

        String rs=null;

        while (FLAG){
             rs = blockingQueue.poll(2L, TimeUnit.SECONDS);

             if (rs==null||rs.equalsIgnoreCase(""))
             {
                 FLAG=false;
                 System.out.println(Thread.currentThread().getName()+"超過兩秒鐘沒取到商品，退出");
                 System.out.println();
                 System.out.println();
                 System.out.println();
                 return;  //
             }
            System.out.println(Thread.currentThread().getName()+"\t 消費佇列"+rs+"成功");
        }

    }


    public  void stop(){
        this.FLAG=false;
    }

}