java 多线程屡次调用start()

public class start {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Thread thread = new Thread(new rund());
		thread.start();
		thread.start();
//		thread.start();
//		thread.start();
	}
	

}
class rund implements Runnable{

	public void run() {
		// TODO Auto-generated method stub
		while(true){
			try {
				Thread.sleep(2000);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
			System.out.println(Thread.currentThread().getName());
		}
	}
	
}

同一个Thread不能重复调用start方法。

一旦线程启动，它就永远不能再从新启动。只有一个新的线程能够被启动，而且只能一次。一个可运行的线程或死线程能够被从新启动。可是仍是会报java.lang.IllegalThreadStateException异常，原先的线程继续执行。

Exception in thread "main" java.lang.IllegalThreadStateException
	at java.lang.Thread.start(Thread.java:705)
	at test.start.main(start.java:13)
Thread-0
Thread-0
Thread-0