java新人，帮看下有关问题分不多请谅解，十一点熄灯前多谢

class ProductorConsumer{    public static void main( String args[] )    {        Resource res=new Resource();// 创建共享资源            new Thread( new Productor(res) ).start();         new Thread( new Consumer(res) ).start();    }}class Resource{    private int account=0;    private boolean flag=false;    public void product()    {        account++;        System.out.println(Thread.currentThread().getName()+"生产"+account);    }    public void pay()    {        System.out.println("/t/t/t"+Thread.currentThread().getName()+"消费"+account);    }}class Productor implements Runnable{    private Resource res;    Productor(Resource res)    {        this.res=res;    }    public synchronized void run()    {        while(res.flag)            try            {                wait();            }            catch (Exception e)            {                System.out.println("error");            }        res.product();        res.flag=true;        this.notifyAll();    }}class Consumer implements Runnable{    private Resource res;    Consumer( Resource res )    {        this.res=res;    }    public synchronized void run()    {        while(!res.flag)            try            {                wait();            }            catch ( Exception e )            {                System.out.println("error");            }        res.pay();        res.flag=false;        this.notifyAll();    }}