经典多线程问题（二）-生产者消费者问题

/**
 * @ClassName Question09
 * @Description: 经典生产者消费者问题
 * @Author xtanb
 * @Date 2019/10/21
 * @Version V1.0
 **/
public class Question09 {
    class CubbyHole{
        private int seq;
        private boolean able = false;

        public synchronized int get(){
            while(!able){
                try {
                    wait();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            able=false;
            notify();
            return seq;
        }

        public synchronized void put(int value){
            while(able){
                try {
                    wait();
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
            seq =value;
            able = true;
            notify();
        }
    }

    class Producer extends Thread{
        private CubbyHole cubbyHole;
        private int number;

        public Producer(CubbyHole c,int number){
            cubbyHole= c;
            this.number=number;
        }
        public void run(){
            for(int i=0;i<10;i++){
                cubbyHole.put(i);
                System.out.println("Productor"+number +" put "+i);
                try {
                    sleep((int)Math.random()*100);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }

    class Consumer extends Thread{
        private CubbyHole cubbyHole;
        private int number;

        public Consumer(CubbyHole cubbyHole, int number) {
            super();
            this.cubbyHole = cubbyHole;
            this.number = number;
        }

        public void run(){
            int value =0;
            for(int i=0;i<10;i++){
                value= cubbyHole.get();
                System.out.println("Customer"+number+" get "+value );
            }
        }
    }
    public static void main(String[] args) {
        CubbyHole cubbyHole = new Question09().new CubbyHole();
        Producer p1 =new Question09().new Producer(cubbyHole, 1);
        Consumer c1 =new Question09().new Consumer(cubbyHole, 1);
        p1.start();
        c1.start();
    }
}

 2.0 reentranlock

package com.example.demo.study.questions;

import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

/**
 * @ClassName Question15
 * @Description: 生产者消费者问题
 * @Author xtanb
 * @Date 2019/10/22
 * @Version V1.0
 **/
class CubbyHoles{
    private volatile boolean flag = true;
    private Lock lock = new ReentrantLock();
    Condition condition = lock.newCondition();
    private int num = 1;

    public void produce(){
        try{
            lock.lock();
            while (!flag){
                condition.await();
            }
            System.out.println("生产"+num);
            flag = false;
            condition.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }

    public void consumer(){
        try{
            lock.lock();
            while (flag){
                try{
                    condition.await();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
            System.out.println("消费"+num);
            num++;
            flag = true;
            condition.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }
}
class Producers extends Thread{
    private CubbyHoles cubbyHole;
    private int number;

    public Producers(CubbyHoles c,int number){
        cubbyHole= c;
        this.number=number;
    }
    public void run(){
        for(int i=0;i<10;i++){
            cubbyHole.produce();
            try {
                sleep((int)Math.random()*100);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }
}

class Consumers extends Thread{
    private CubbyHoles cubbyHole;
    private int number;

    public Consumers(CubbyHoles cubbyHole, int number) {
        super();
        this.cubbyHole = cubbyHole;
        this.number = number;
    }

    public void run(){
        for(int i=0;i<10;i++){
            cubbyHole.consumer();
        }
    }
}

public class Question15 {
    public static void main(String[] args) {
        CubbyHoles cubbyHoles = new CubbyHoles();
        new Producers(cubbyHoles,1).start();
        new Consumers(cubbyHoles,1).start();
    }
}