使用 Lock Condition 实现产生者消费者

一、Clerk2类：

package com.yao.thread.syn;

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

public class Clerk2 {
	private int product = -1; //-1表示没有任何产品
	private Lock lock = new ReentrantLock();
	private Condition condition = lock.newCondition();
	
	public void setProduct(int product){
		try{
			lock.lock();
			while (this.product != -1) {
				try {
					condition.await();
				} catch (InterruptedException e) {
					throw new RuntimeException(e);
				}
			}
			this.product = product;
			System.out.printf("生产者设定 %d %n",this.product);
			condition.signal();
		}finally{
			lock.unlock();
		}
		
	}
	
	public int getProduct(){
		try{
			lock.lock();
			while (this.product == -1) {
				try {
					condition.await();
				} catch (InterruptedException e) {
					throw new RuntimeException();
				}
			}
			int temp = this.product;
			System.out.printf("消费者取走 %d %n",temp);
			this.product = -1;
			condition.signal();
			return temp;
		}finally{
			lock.unlock();
		}
	}
}

二、Producter2类：

package com.yao.thread.syn;

public class Producter2 implements Runnable {

	private Clerk2 clerk;
	
	public Producter2(Clerk2 clerk){
		this.clerk = clerk;
	}
	
	@Override
	public void run() {
		System.out.println("生产者开始产生整数");
		for (int i = 0 ; i < 10 ; i++) {
			try {
				Thread.sleep((int)(Math.random()*3000));
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			clerk.setProduct(i);
		}
	}

}

三、Consumer2类：

package com.yao.thread.syn;

public class Consumer2 implements Runnable {

	private Clerk2 clerk;
	public Consumer2(Clerk2 clerk){
		this.clerk = clerk;
	}
	@Override
	public void run() {
		System.out.println("消费都可以消费整数");
		for (int i = 0 ; i < 10 ; i++) {
			try {
				Thread.sleep((int)(Math.random()*3000));
			} catch (InterruptedException e) {
				e.printStackTrace();
			}
			clerk.getProduct();
		}
	}

}

四、演示类：

package com.yao.thread.syn;

public class ConsumerProducterDemo2 {

	public static void main(String[] args) {
		Clerk2 clerk2 = new Clerk2();
		Consumer2 consumer = new Consumer2(clerk2);
		Producter2 producter = new Producter2(clerk2);
		new Thread(consumer).start();
		new Thread(producter).start();
	}

}

这里的实现方式和传统的差不多一样，效率也差不多，只不过灵活许多。