# Timer Service

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Published 2022-12-03

This tutorial explains ou what a Timer Service in EJB is.

In order to create a timer in your Java EJB in the programmatically you have to inject the TimerService into your EJB using @Resource.

Here it is an example of Timer Service in Java/ EJB :

package ejb;
 
import java.util.Date;
 
import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import javax.ejb.Singleton;
import javax.ejb.Startup;
import javax.ejb.Timeout;
import javax.ejb.Timer;
import javax.ejb.TimerService;
 
@Singleton
@Startup
public class AddIntegers implements AddIntegersRemoteInterface {
     
    @Resource
    private TimerService timerService;
 
    @PostConstruct
        private void init() {
            timerService.createTimer(5000, 5000, null);
        }
 
    @Timeout
    public void execute(Timer timer) {
        System.out.println("Java procedure executed at " + new Date());
        System.out.println(returnSuma(1,3));
        System.out.println("____________________________________________");
    }
    
    @Override
    public int returnSuma(int a, int b) {
        // What the EJB3 will return
        return a+b;
    }
}

This EJB will run the execute(Timer timer) method at every 5 seconds.

Using annotations to create a scheduled task is really easy as well. Take an EJB, add one @Schedule annotation or multiple @Schedule annotations as parameters of a @Schedules annotation to a method. Adding a Scheduler to an EJB is similar to adding a Timer.