Java生产者和消费者问题

import java.util.*;

public class ProductCustoms {
public static void main(String[] args) {
SyncStack ss = new SyncStack();
Producer p = new Producer(ss);
Consumer c = new Consumer(ss);
new Thread(p).start();
new Thread(c).start();
}

}

class Tomato

{
int id;
Tomato(int id)
{
this.id=id;
}
public String toString()
{
return "WoTou:"+id;
}

}

class SyncStack

{
int index=0;
Tomato[] arrWT=new Tomato[6];
public synchronized void push(Tomato wt)
{
while(index==arrWT.length)//防止catch到异常，再去检查；
{
try {
this.wait();//当前的正在访问这个对象的线程wait；只有方法被锁才能wait
} catch (InterruptedException e) {
e.printStackTrace();
}
}
this.notify();//谁现在正在对象上等待就叫醒一个线程让它继续执行；
arrWT[index++]=wt;
}
public synchronized Tomato pop() 
{
while(index==0)
{
try {
this.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
this.notify();
index--;
return arrWT[index];
}

}

class Producer implements Runnable

{
SyncStack ss = null;
Producer(SyncStack ss)
{
this.ss=ss;
}

public void run() {
for(int i=0;i<20;i++)
{
Tomato wt = new Tomato(i);
ss.push(wt);
System.out.println("生产了："+wt);
try {
Thread.sleep((long) (Math.random()*1000));
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}

}

class Consumer implements Runnable

{
SyncStack ss = null;
Consumer(SyncStack ss)
{
this.ss=ss;
}
public void run() {
for(int i=0;i<20;i++)
{
Tomato wt=ss.pop();
System.out.println("消费了："+wt);
try {
Thread.sleep((long) (Math.random()*1000));
} catch (InterruptedException e) {
e.printStackTrace();
}

}
}

}