Java 模拟生产者消费者问题

模拟生产者-消费者问题的UNL图：

图3 生产者-消费者UML

图3为模拟生产者-消费者的UML图，Product类为生产者产生的产品类，Producer类为生产者，Consumer类为消费者，QueueMessage类用来存储多个生

产者产生产品以及提供多个消费者消费产品。Test类来测试“生产者-消费者”模拟系统。

3、模拟生产者-消费者问题的程序清单

package imut.cstd.j09_2.shiyan3;

public class Product { //产品类 private String pname; }

public String getPname(){ }

public void setPname(String pname){ }

this.pname = pname; return pname;

package imut.cstd.j09_2.shiyan3; import java.util.LinkedList;

public class QueueMessage { //共享区类 private static int num = 0;

private final static int MAX_num = 30;//上线商品

private LinkedListqueue = new LinkedList();

public boolean isEmpty(){ }

public synchronized Product get(){

Product temp = null; if(queue.isEmpty()){

System.out.println(Thread.currentThread().getName()+\"消费者return queue.isEmpty();

\"+\":\"+\"目前没有可消费的商品！\"); try{

}

else if(!queue.isEmpty()){

}

this.wait();

System.out.println(e.getMessage()); }catch (InterruptedException e) {

try { }

System.out.println(Thread.currentThread().getName()+\"消费者

num--;

temp = queue.poll(); this.wait();

System.out.println(e.getMessage());

} catch (InterruptedException e) {

\"+\"\消费的商品号：\"+temp.getPname()+\"\目前商品的数量是：\"+num); }

}

public synchronized void add(Product temp){

if(numnum++;

this.queue.add(temp);

System.out.println(Thread.currentThread().getName()+\"生产者this.notifyAll(); return temp;

\"+\"\产生的商品号：\"+temp.getPname()+\"\目前商品的数量是：\"+num); }

else if(num>MAX_num){

System.out.println(\"生产的商品的数量已经满足：\"+num+\"生产者

\"+Thread.currentThread().getName()+\"产生的商品存不了了！\"); try{ }

}

}

this.notifyAll();

}

this.wait();

e.printStackTrace();

}catch(InterruptedException e){

package imut.cstd.j09_2.shiyan3;

public class Producer implements Runnable{ //生产者类 private QueueMessage queue ;

public QueueMessage getQueue(){

return queue; }

public void setQueue(QueueMessage queue){ this.queue = queue; } }

public synchronized void run() {

product.setPname(Thread.currentThread().getName()+\"--->\"+(i+1)+\"\\ }

}

queue.add(product); try{ }

Thread.sleep(200);

System.out.println(e.getMessage()); System.out.println(e.getMessage()); }catch(InterruptedException e){ }catch(NullPointerException e){ for(int i = 0;i<20;i++){

Product product = new Product();

t\");

package imut.cstd.j09_2.shiyan3;

public class Consumer implements Runnable{ //消费者类 private QueueMessage queue = null;

public QueueMessage getQueue(){ return queue; }

public void setQueue(QueueMessage queue){ this.queue = queue; }

public void run() {

for(int i = 0;i<20;i++){

queue.get(); try{

Thread.sleep(200);

System.out.println(e.getMessage()); }catch(InterruptedException e){ }catch(NullPointerException e){

}

}

}

}

System.out.println(e.getMessage());

package imut.cstd.j09_2.shiyan3;

public class Test {

public static void main(String[] args){ //测试类 QueueMessage queue = new QueueMessage() ;

Producer producer = new Producer(); producer.setQueue(queue);

Consumer consumer = new Consumer();

consumer.setQueue(queue);

Thread p = new Thread(producer); Thread p1 = new Thread(producer); Thread p2 = new Thread(producer); p.setName(\"p\"); //定义了三个消费者 p1.setName(\"p1\"); p2.setName(\"p2\");

p.start();p1.start();p2.start(); Thread c = new Thread(consumer); Thread c1 = new Thread(consumer);

c.setName(\"c\"); c1.setName(\"c1\");//定义了两个生产者 c.start();c1.start(); }

}