多次启动一个线程是非法的

class Ticket implements Runnable {
    //1.描述票的数量
    private int tickets = 100;
    
    //2.售票的动作,这个动作需要被多线程执行,那就是线程任务代码,需要定义run方法中
    //线程任务中通常都有循环结构
    public void run() {
        while (true) {
            if (tickets > 0) {
                System.out.println(Thread.currentThread().getName() + tickets--);
            }
        }
        
    }
}


public class ThreadDemo3 {
    public static void main(String[] args) {
        //1.创建Runnable接口的子类对象
        Ticket t = new Ticket();
        //2创建4个线程对象,并将Runnable接口的子类对象作为参数传递给Thread的构造函数
        Thread t1 = new Thread(t);
        //Thread t2 = new Thread(t);
        //Thread t3 = new Thread(t);
        //Thread t4 = new Thread(t);
        
        //3.开启4个线程
        t1.start();
        t1.start();
        t1.start();
        t1.start();
        
        
    }
}