解析时已到达文件结尾

class TWindow implements Runnable{
	private int ticketNum =100;
	
	public void run(){
		while(true){
			if(ticketNum > 0)
				System.out.println(Thread.currentThread().getName()
				+" sale "+ ticketNum--);
		}
	
}

class ThreadDemo{
	public static void main(String[] args){
		TWindow t = new TWindow();
		
		Thread t1 = new Thread(t);
		Thread t2 = new Thread(t);
		Thread t3 = new Thread(t);
		Thread t4 = new Thread(t);
		
		t1.start();
		t2.start();
		t3.start();
		t4.start();
	}
}

该程序编译不通过，提示如图