Timer

import java.util.Timer;

public class Test1 {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		        run();   
	}
	private static void run() {   
        Timer timer = new Timer();   
        Test2 timerTask = new Test2();   
        timer.schedule(timerTask, 0, 5000);   
    }   

}

import java.util.Random;
import java.util.TimerTask;


		public class Test2 extends TimerTask {   
			  
		    @Override  
		    public void run() {   
		        message();
		    }   
		    public void message() {
		    	System.out.println("nihao");
		    }

	}