RetriableTrigger

package com.lashpoint.quartz;import java.util.Calendar;import java.util.Date;import org.quartz.JobExecutionContext;import org.quartz.JobExecutionException;import org.quartz.SchedulerException;import org.quartz.SimpleTrigger;import com.lashpoint.twitter.quartz.RescheduleException;public abstract class RetriableTrigger extends SimpleTrigger {	/**	 * 	 */	private static final long serialVersionUID = 2986291750485640660L;		private static final int DELAY_CEILING = 600; // 15 minutes	private static final int DELAY_EXP_BASE = 2; // Delays will be a power of 2		public RetriableTrigger(String name, Date startDate) {		super(name, startDate, null, 0, 0);	}		@Override	public boolean hasAdditionalProperties() {		return true;	}		@Override	public int executionComplete(JobExecutionContext context,			JobExecutionException result) {		if (shouldReschedule(context, result)) {			try {    			SimpleTrigger nextTrigger = createTriggerForReschedule(context,    					result);    			if (nextTrigger != null) {					context.getScheduler().rescheduleJob(getName(), getGroup(),							nextTrigger);										return INSTRUCTION_NOOP;				}			}						catch (SchedulerException e) {				throw new RescheduleException(e);			}		}				return INSTRUCTION_DELETE_TRIGGER;	}		protected abstract boolean shouldReschedule(JobExecutionContext context,			JobExecutionException result);		protected SimpleTrigger createTriggerForReschedule(JobExecutionContext context,			JobExecutionException result) {		try {			SimpleTrigger trigger = getClass().newInstance();						Calendar nextFireTime = Calendar.getInstance();			nextFireTime.add(Calendar.SECOND, Math.min(DELAY_CEILING,					(int)Math.pow(DELAY_EXP_BASE, getTimesTriggered())));						trigger.setStartTime(nextFireTime.getTime());			trigger.setJobName(getJobName());			trigger.setJobGroup(getJobGroup());			trigger.setTimesTriggered(getTimesTriggered());						return trigger;		}		catch (InstantiationException e) {			throw new RescheduleException(e);		}		catch (IllegalAccessException e) {			throw new RescheduleException(e);		}	}}