传统版生产者和消费者vs阻塞队列版生产者和消费者

使用jdk中的lock和condition机制实现生产者和消费者

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

public class ProducerConsumerTraditional {

    public static void main(String[] args) {

        final Resources r = new Resources();

        new Thread(() -> {
            for(int i = 1; i <= 5; i ++){
                r.increment();
            }
        },"producer").start();

        new Thread(() -> {
            for(int i = 1; i <= 5; i ++){
                r.decrement();
            }
        },"consumer").start();
    }
}

class Resources{
    //规定，0 我们就开始生产 1 我们就进行消费
    private int number = 0;
    private Lock lock = new ReentrantLock();
    private Condition condition = lock.newCondition();
    //对number进行加一操作 生产者
    public void increment(){
        lock.lock();
        try {
            while(number != 0){
                condition.await();
            }
            number ++;
            System.out.println(Thread.currentThread().getName() + "\t" + number);
            //通知消费者消费
            condition.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }

    //对number进行减一 消费者
    public void decrement(){
        lock.lock();
        try {
            while(number == 0){
                condition.await();
            }
            number --;
            System.out.println(Thread.currentThread().getName() + "\t" + number);
            //通知生产者生产
            condition.signal();
        } catch (InterruptedException e) {
            e.printStackTrace();
        } finally {
            lock.unlock();
        }
    }
}

---

使用BlockingQueue实现升级版的生产者和消费者

import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;

public class ProdAndConsumerBlockingQueue {

    public static void main(String[] args) throws Exception {
        BlockingQueue<String> blockingQueue = new ArrayBlockingQueue<>(3);
        MyResources resources = new MyResources(blockingQueue);
        new Thread(() -> {
            System.out.println("生产线程启动");
            try {
                resources.producer();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        },"producer").start();

        new Thread(() -> {
            System.out.println("消费线程启动");
            try {
                resources.consumer();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        },"consumer").start();

        TimeUnit.SECONDS.sleep(5);

        resources.stop();
    }
}

class MyResources{

    private volatile boolean flag = true;
    AtomicInteger number = new AtomicInteger(0);
    BlockingQueue<String> blockingQueue = null;

    public MyResources(BlockingQueue<String> blockingQueue){
        this.blockingQueue = blockingQueue;
        System.out.println(blockingQueue.getClass().getName());
    }

    public void producer() throws InterruptedException {
        String data = null;
        boolean b ;
        while(flag){
            data = number.incrementAndGet() + "";
            //放入blockQueue中
            b = blockingQueue.offer(data,2L,TimeUnit.SECONDS);
            if(b) {
                System.out.println(Thread.currentThread().getName() + "\t" + "放入队列" + data + "成功！");
            }else{
                System.out.println(Thread.currentThread().getName() + "\t" + "放入队列" + data + "失败！");
            }
            TimeUnit.SECONDS.sleep(1);
        }
        System.out.println(Thread.currentThread().getName() + "\t" + "生产终止");
    }


    public void consumer() throws InterruptedException {
        String result = null;
        while(flag){
            result = blockingQueue.poll(2L,TimeUnit.SECONDS);
            if(null == result || "".equalsIgnoreCase(result)){
                flag = false;
                System.out.println(Thread.currentThread().getName() + "\t" + "超过2秒，消费退出");
                return;
            }
            System.out.println(Thread.currentThread().getName() + "\t" + "取出队列" + result + "成功！");
        }
    }

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

}