线程并发问题

package edu.wtbu;
//多个线程同时操作同一个对象
//买火车票的例子
//问题：多个线程操作同一个资源的情况下，线程不安全，数据紊乱
public class Demo01 implements Runnable{
    private int ticketNum=10;//票数
    @Override
    public void run() {
        while (true){
            if(ticketNum<=0){
                break;
            }
            try {
                Thread.sleep(200);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
            System.out.println(Thread.currentThread().getName()+"-->拿到了第"+ticketNum--+"票");
        }
    }

    public static void main(String[] args) {
        Demo01 ticket = new Demo01();
        new Thread(ticket,"小明").start();
        new Thread(ticket,"小红").start();
        new Thread(ticket,"小光").start();
    }
}