Web Development

package session.TimerBean;

import javax.annotation.Resource;
import javax.ejb.SessionContext;
import javax.ejb.Stateless;
import javax.ejb.Timeout;
import javax.ejb.Timer;
import javax.ejb.TimerService;
import javax.ejb.TransactionManagement;
import javax.ejb.TransactionManagementType;



/**
 * Session Bean implementation class Timer
 */
@Stateless
@TransactionManagement(TransactionManagementType.BEAN)
public class Timers implements TimerLocal{
	@Resource
	private SessionContext roe;
	private TimerService ts;

    /**
     * Default constructor. 
     */
    public Timers() {
        // TODO Auto-generated constructor stub
    	
    }
    public void TimerB()
    {
    	<big>Timer time = ts.createTimer(6000, null);</big>
    	System.out.println("checking");
   
    }
    
    @Timeout
    public void WorkingTimer(Timer time)
    {
    	System.out.println("Timer Bean is working!!!!");
    }
}

Exception in thread "main" java.lang.NullPointerException
	at session.TimerBean.Timers.TimerB(Timers.java:33)
	at client.session.TimerBean.Client.main(Client.java:12)