JAVA线程的使用

Eg:三个售票站同时卖20张票

import java.util.*;

class Station implements Runnable{
    int ticket=0;//SellTicket所用到的参数,三个票站公用一个ticket,用number-ticket表示剩余票数
    String s1,s2,s3;
    public Station(String s1,String s2,String s3)
    {
        this.s1=s1;
        this.s2=s2;
        this.s3=s3;
    }
    @Override
    public void run() {
        // TODO Auto-generated method stub
        while(true)
        {
                SellTicket(20); 
        }
    }
    public synchronized void SellTicket(int number)
    {
        if(Thread.currentThread().getName().equals(s1)) 
        {
            ticket++;
            if(ticket>number)
                {   return; }

            System.out.println("一号窗口卖出第"+ticket+"张票"+"还剩"+(number-ticket)+"张票");
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        else if(Thread.currentThread().getName().equals(s2)) 
        {
            ticket++;
            if((ticket>number))
                { return;  }

            System.out.println("二号窗口卖出第"+ticket+"张票"+"还剩"+(number-ticket)+"张票");
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }   
        }
        else if(Thread.currentThread().getName().equals(s3)) 
        {
            ticket++;
            if((ticket>number))
                { return; } 

            System.out.println("三号窗口卖出第"+ticket+"张票"+"还剩"+(number-ticket)+"张票");
            try {
                Thread.sleep(100);
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }   
    }   
}

public class Main{
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        String s1="一号窗口",s2="二号窗口",s3="三号窗口";
        Station s=new Station(s1,s2,s3);
        Thread m=new Thread(s);
        Thread n=new Thread(s);
        Thread q=new Thread(s);
        m.setName(s1);
        n.setName(s2);
        q.setName(s3);
        m.start();
        n.start();
        q.start();
    }
}