Java项目练习6_实现生产者消费者模型

(上一节练习，自定义异常）

Java项目练习：第6期

实现生产者消费者模型（60分钟）

需求描述：

在一个系统中，存在生产者和消费者两种角色，他们通过内存缓冲区进行通信，生产者生产消费者需要的资料，消费者把资料做成产品，先要求模拟实现一个生产者消费者模型，具体要求如下： 

1. 生产者与消费者线程独立，通过不同线程实现
2. 内存缓冲区为空的时候消费者必须等待，而内存缓冲区满的时候，生产者必须等待
3. 多线程对临界区资源的操作时候必须保证在读写中只能存在一个线程

考查知识点：

• Java多线程的概念及其基本使用方法
• 并发同步与互斥基础
• 集合类与并发集合的高级特性 

package d20180926;

import java.text.MessageFormat;
import java.util.Random;
import java.util.concurrent.*;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * 容器数据类型
 * @author ctk
 *
 */
class PCData {
    private final int intData;
    public PCData(int d){
        intData = d;
    }
    public PCData(String d){
        intData = Integer.valueOf(d);
    }
    public int getData(){
        return intData;
    }
    public String toString(){
        return "data:"+intData;
    }
}
/**
 * 生产者
 * @author ctk
 * 生产者消费者模型
 */
class Producer implements Runnable {
    private volatile boolean isRunning = true;
    private BlockingQueue queue;// 内存缓冲区
    private static AtomicInteger count = new AtomicInteger();// 总数 原子操作
    private static final int SLEEPTIME = 1000;
    public Producer(BlockingQueue queue) {
        this.queue = queue;
    }
    public void run() {
        PCData data = null;
        Random r = new Random();
        System.out.println("start producting id:" + Thread.currentThread().getId());
        try {
            while (isRunning) {
                Thread.sleep(r.nextInt(SLEEPTIME));
                data = new PCData(count.incrementAndGet());
                System.out.println(data + " 加入队列");
                if (!queue.offer(data, 2, TimeUnit.SECONDS)) {
                    System.err.println(" 加入队列失败");
                }
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
            Thread.currentThread().interrupt();
        }
    }
    public void stop() {
        isRunning = false;
    }
}
/**
 * 消费者
 * @author ctk
 */
class Consumer implements Runnable{
    private BlockingQueue queue;
    private static final int SLEEPTIME = 1000;
    public Consumer(BlockingQueue queue){
        this.queue = queue;
    }
    public void run() {
        System.out.println("start Consumer id :"+Thread.currentThread().getId());
        Random r = new Random();
        try{
            while(true){
                PCData data = queue.take();
                if(data != null)
                {
                    int re = data.getData() * data.getData();
                    System.out.println(MessageFormat.format("{0}*{1}={2}", data.getData(),data.getData(),re));
                    Thread.sleep(r.nextInt(SLEEPTIME));
                }
            }
        }catch (InterruptedException e) {
            e.printStackTrace();
            Thread.currentThread().interrupt();
        }
    }
}
/**
 * 主测试函数
 * @author ctk
 *
 */
public class Main {
    public static void main(String[] args) throws InterruptedException {
        BlockingQueue queue = new LinkedBlockingDeque<>(10);
        Producer p1 = new Producer(queue);
        Producer p2 = new Producer(queue);
        Producer p3 = new Producer(queue);
        Consumer c1 = new Consumer(queue);
        Consumer c2 = new Consumer(queue);
        Consumer c3 = new Consumer(queue);
        ExecutorService service = Executors.newCachedThreadPool();
        service.execute(p1);
        service.execute(p2);
        service.execute(p3);
        service.execute(c1);
        service.execute(c2);
        service.execute(c3);
        Thread.sleep(10*1000);
        p1.stop();
        p2.stop();
        p3.stop();
        Thread.sleep(3000);
        service.shutdown();
    }
}

(下一节练习，设计实现一个线程池）