It's a very powerful mechanism to create different kind of schedule.
As we know, Timer Service can close task for scheduling like monthly report generation, sever checking, birthday notification for customer etc. Approach of the service is very similar to Unix cron utility. We can use the same parameters for describing time period of schedule.
Generally, we can describe our schedule using declarative and programmatic approach. In our case,
it's declarative description using @Schedule annotation.
package ejb.timer;
import jakarta.ejb.Schedule;
import jakarta.ejb.Stateless;
import java.util.Date;
@Stateless
public class StatisticsEJB {
@Schedule(hour = "*", minute = "*/1")
public void sendMinutesServerStatistics() {
System.out.println("Your server is alive at: " + new Date());
}
}As example, we want to create schedule, which will be checked the server statistic we just add one annotation and period description similar to cron utility.