消费者生产者模式

1.synchronized——wait——notifyAll组合

public class ConsumerDemo2 {
    public int number = 0;
    //public Lock lock = new ReentrantLock();
    //public Condition condition = lock.newCondition();

    public synchronized void increase() throws Exception{
        while(number != 0){
           this.wait();
        }
        number++;
        System.out.println(Thread.currentThread().getName()+"\t"+number);
        this.notifyAll();
    }


    public synchronized void decrease() throws Exception{
        while(number == 0){
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName()+"\t"+number);
        this.notifyAll();
    }

    public static void main(String[] args) {
        ConsumerDemo2 consumerDemo = new ConsumerDemo2();
        new Thread(()->{
            for(int i=0;i<5;i++){
                try{
                    consumerDemo.increase();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        },"A").start();
        new Thread(()->{
            for(int i=0;i<5;i++){
                try{
                    consumerDemo.decrease();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        },"B").start();
    }

}

2.lock——await——signalAlll组合

public class ConsumerDemo2 {
    public int number = 0;
    //public Lock lock = new ReentrantLock();
    //public Condition condition = lock.newCondition();

    public synchronized void increase() throws Exception{
        while(number != 0){
           this.wait();
        }
        number++;
        System.out.println(Thread.currentThread().getName()+"\t"+number);
        this.notifyAll();
    }


    public synchronized void decrease() throws Exception{
        while(number == 0){
            this.wait();
        }
        number--;
        System.out.println(Thread.currentThread().getName()+"\t"+number);
        this.notifyAll();
    }

    public static void main(String[] args) {
        ConsumerDemo2 consumerDemo = new ConsumerDemo2();
        new Thread(()->{
            for(int i=0;i<5;i++){
                try{
                    consumerDemo.increase();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        },"A").start();
        new Thread(()->{
            for(int i=0;i<5;i++){
                try{
                    consumerDemo.decrease();
                }catch (Exception e){
                    e.printStackTrace();
                }
            }
        },"B").start();
    }

}

3.按a-b-c顺序打印，先打印A 5次，然后打印B 10次，然后打印C 15次

package prodecerConsumer;

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

public class ConsumerDemo3 {
    public int number = 1;
    public Lock lock = new ReentrantLock();
    public Condition c1 = lock.newCondition();
    public Condition c2 = lock.newCondition();
    public Condition c3 = lock.newCondition();

    public void print5(){
        lock.lock();
        try{
            while(number != 1){
                c1.await();
            }

            for(int i=1;i<=5;i++) {
                System.out.println(Thread.currentThread().getName() + "\t"+i);
            }
            number = 2;
            c2.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }

    public void print10(){
        lock.lock();
        try{
            while(number != 2){
                c2.await();
            }

            for(int i=1;i<=10;i++) {
                System.out.println(Thread.currentThread().getName() + "\t"+i);
            }
            number = 3;
            c3.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }

    public void print15(){
        lock.lock();
        try{
            while(number != 3){
                c3.await();
            }
            for(int i=1;i<=15;i++) {
                System.out.println(Thread.currentThread().getName() + "\t"+i);
            }
            number = 1;
            c1.signal();
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            lock.unlock();
        }
    }

    public static void main(String[] args) {
        ConsumerDemo3 consumerDemo = new ConsumerDemo3();
        new Thread(()->{
            for(int i=0;i<5;i++){
                consumerDemo.print5();
            }
        },"A").start();
        new Thread(()->{
            for(int i=0;i<5;i++){
                consumerDemo.print10();
            }
        },"B").start();
        new Thread(()->{
            for(int i=0;i<5;i++){
                consumerDemo.print15();
            }
        },"C").start();
    }

}

4.阻塞队列（重点）

package prodecerConsumer;



import java.lang.annotation.Retention;
import java.util.concurrent.ArrayBlockingQueue;

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class ConsumerDemo5 {
    public volatile boolean flag = true;//可见性
    public AtomicInteger atomicInteger = new AtomicInteger();
    BlockingQueue<String> blockingQeque = null;//接口扩展性

    public ConsumerDemo5(BlockingQueue<String> blockingQeque) {
        this.blockingQeque = blockingQeque;
        System.out.println(blockingQeque.getClass().getName());//反射获取当前日志考虑
    }

    public void producer() throws Exception {
        String data = null;
        boolean retValue;
        while (flag) {
            data = atomicInteger.incrementAndGet() + "";
            retValue = blockingQeque.offer(data, 2L, TimeUnit.SECONDS);
            if (retValue) {
                System.out.println(Thread.currentThread().getName() + "插入队列 " + data + "成功");
            } else {
                System.out.println(Thread.currentThread().getName() + "插入队列 " + data + "失败");
            }
            TimeUnit.SECONDS.sleep(1);
        }
        System.out.println("producer 生产结束");
    }


    public void consumer() throws Exception {
        String result = null;
        while (flag) {
            result = blockingQeque.poll(2L, TimeUnit.SECONDS);
            if (null == result || result.equalsIgnoreCase("")) {
                flag = false;
                System.out.println(Thread.currentThread().getName() + " 超过2s没有取到数据，消费退出");
                return;
            }
            System.out.println(Thread.currentThread().getName() + "消费队列 " + result + "成功");

        }
    }

    public void stop() {
        flag = false;
    }

    public static void main(String[] args) {
        ConsumerDemo5 consumerDemo5 = new ConsumerDemo5(new ArrayBlockingQueue<>(10));
        new Thread(() -> {
            try {
                consumerDemo5.producer();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }, "producer").start();

        new Thread(() -> {
            try {
                consumerDemo5.consumer();
            } catch (Exception e) {
                e.printStackTrace();
            }
        }, "consumer").start();

        try {
            TimeUnit.SECONDS.sleep(5);//等待五秒钟结束
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("活动结束");
        consumerDemo5.stop();

    }
}