java多线程模拟火车售票问题————实验练习

通过java多线程模拟火车售票，开始的错误程序
//售票类
class Runner implements Runnable{


private int Ticketnum=10;
int id;
Runner(int id){
this.id=id;
}
synchronized void SellTic(){
if(Ticketnum<=0){return;}
else {
System.out.println(Thread.currentThread().getName()+" sale "+Ticketnum--);
}
}
public void run(){
while(Ticketnum>0){
try{Thread.sleep(100);}catch(InterruptedException e){}; 
SellTic();
}
}
}
//测试类
public class Ticket {
public static void main(String args[]){
Thread t1 =new Thread(new Runner(1));
Thread t2 =new Thread(new Runner(2));
Thread t3 =new Thread(new Runner(3));
Thread t4 =new Thread(new Runner(4));
Thread t5 =new Thread(new Runner(5));
t1.start();
t2.start();
t3.start();
t4.start();
t5.start();

}
}


输出结果五个线程没有共享Ticketnum变量，出现重复售票，错误原因在售票类中Ticketnum变量不是静态变量，即使值修改以后无法保留。改为，
private static int Ticketnum=10;问题解决
涉及线程共享问题要注意变量的全局性；