多執行緒安全問題（賣火車票案例）

package com.cppdy;

class MyThread5 implements Runnable{

    private Integer ticketCount=100;
    @Override
    public void run() {
        while(ticketCount>0) {
            try {
                Thread.sleep(50);
            } catch (Exception e) {
                e.printStackTrace();
            }
            sale();
        }
    }
    
    
 
public void sale() {
        System.out.println(Thread.currentThread().getName()+"賣出了第："+(100-ticketCount+1)+"張票。");
        ticketCount--;
    }
}

public class ThreadDemo5 {

    public static void main(String[] args) throws Exception{
        MyThread5 mt = new MyThread5();
        Thread thread1 = new
 
 Thread(mt,"視窗1");
        Thread thread2 = new Thread(mt,"視窗2");
        thread1.start();
        thread2.start();
    }

}