simpletrigger.java

Quartz is a full-featured, open source job scheduling system that can be integrated with, or used al

            if(nextFireTime != null && nextFireTime.before(now)) {
                long diff = now.getTime() - nextFireTime.getTime();
                if(diff >= misfireThreshold) {
                    nextFireTime = getFireTimeAfter(nextFireTime);
                }
            }
        }
    }

    /**
     * <p>
     * Called by the scheduler at the time a <code>Trigger</code> is first
     * added to the scheduler, in order to have the <code>Trigger</code>
     * compute its first fire time, based on any associated calendar.
     * </p>
     * 
     * <p>
     * After this method has been called, <code>getNextFireTime()</code>
     * should return a valid answer.
     * </p>
     * 
     * @return the first time at which the <code>Trigger</code> will be fired
     *         by the scheduler, which is also the same value <code>getNextFireTime()</code>
     *         will return (until after the first firing of the <code>Trigger</code>).
     *         </p>
     */
    public Date computeFirstFireTime(Calendar calendar) {
        nextFireTime = getStartTime();

        while (nextFireTime != null && calendar != null
                && !calendar.isTimeIncluded(nextFireTime.getTime())) {
            nextFireTime = getFireTimeAfter(nextFireTime);
            
            if(nextFireTime == null)
            	break;
            
            //avoid infinite loop
            java.util.Calendar c = java.util.Calendar.getInstance();
            c.setTime(nextFireTime);
            if (c.get(java.util.Calendar.YEAR) > YEAR_TO_GIVEUP_SCHEDULING_AT) {
                return null;
            }
        }
        
        return nextFireTime;
    }

    /**
     * <p>
     * Called after the <code>{@link Scheduler}</code> has executed the
     * <code>{@link org.quartz.JobDetail}</code> associated with the <code>Trigger</code>
     * in order to get the final instruction code from the trigger.
     * </p>
     * 
     * @param context
     *          is the <code>JobExecutionContext</code> that was used by the
     *          <code>Job</code>'s<code>execute(xx)</code> method.
     * @param result
     *          is the <code>JobExecutionException</code> thrown by the
     *          <code>Job</code>, if any (may be null).
     * @return one of the Trigger.INSTRUCTION_XXX constants.
     * 
     * @see #INSTRUCTION_NOOP
     * @see #INSTRUCTION_RE_EXECUTE_JOB
     * @see #INSTRUCTION_DELETE_TRIGGER
     * @see #INSTRUCTION_SET_TRIGGER_COMPLETE
     * @see #triggered(Calendar)
     */
    public int executionComplete(JobExecutionContext context,
            JobExecutionException result) {
        if (result != null && result.refireImmediately()) {
            return INSTRUCTION_RE_EXECUTE_JOB;
        }

        if (result != null && result.unscheduleFiringTrigger()) {
            return INSTRUCTION_SET_TRIGGER_COMPLETE;
        }

        if (result != null && result.unscheduleAllTriggers()) {
            return INSTRUCTION_SET_ALL_JOB_TRIGGERS_COMPLETE;
        }

        if (!mayFireAgain()) {
            return INSTRUCTION_DELETE_TRIGGER;
        }

        return INSTRUCTION_NOOP;
    }

    /**
     * <p>
     * Returns the next time at which the <code>Trigger</code> is scheduled to fire. If
     * the trigger will not fire again, <code>null</code> will be returned.  Note that
     * the time returned can possibly be in the past, if the time that was computed
     * for the trigger to next fire has already arrived, but the scheduler has not yet
     * been able to fire the trigger (which would likely be due to lack of resources
     * e.g. threads).
     * </p>
     *
     * <p>The value returned is not guaranteed to be valid until after the <code>Trigger</code>
     * has been added to the scheduler.
     * </p>
     *
     * @see TriggerUtils#computeFireTimesBetween(Trigger, Calendar, Date, Date)
     */
    public Date getNextFireTime() {
        return nextFireTime;
    }

    /**
     * <p>
     * Returns the previous time at which the <code>SimpleTrigger</code> 
     * fired. If the trigger has not yet fired, <code>null</code> will be
     * returned.
     */
    public Date getPreviousFireTime() {
        return previousFireTime;
    }

    /**
     * <p>
     * Set the next time at which the <code>SimpleTrigger</code> should fire.
     * </p>
     * 
     * <p>
     * <b>This method should not be invoked by client code.</b>
     * </p>
     */
    public void setNextFireTime(Date nextFireTime) {
        this.nextFireTime = nextFireTime;
    }

    /**
     * <p>
     * Set the previous time at which the <code>SimpleTrigger</code> fired.
     * </p>
     * 
     * <p>
     * <b>This method should not be invoked by client code.</b>
     * </p>
     */
    public void setPreviousFireTime(Date previousFireTime) {
        this.previousFireTime = previousFireTime;
    }

    /**
     * <p>
     * Returns the next time at which the <code>SimpleTrigger</code> will
     * fire, after the given time. If the trigger will not fire after the given
     * time, <code>null</code> will be returned.
     * </p>
     */
    public Date getFireTimeAfter(Date afterTime) {
        if (complete) {
            return null;
        }

        if ((timesTriggered > repeatCount)
                && (repeatCount != REPEAT_INDEFINITELY)) {
            return null;
        }

        if (afterTime == null) {
            afterTime = new Date();
        }

        if (repeatCount == 0 && afterTime.compareTo(getStartTime()) >= 0) {
            return null;
        }

        long startMillis = getStartTime().getTime();
        long afterMillis = afterTime.getTime();
        long endMillis = (getEndTime() == null) ? Long.MAX_VALUE : getEndTime()
                .getTime();

        if (endMillis <= afterMillis) {
            return null;
        }

        if (afterMillis < startMillis) {
            return new Date(startMillis);
        }

        long numberOfTimesExecuted = ((afterMillis - startMillis) / repeatInterval) + 1;

        if ((numberOfTimesExecuted > repeatCount) && 
            (repeatCount != REPEAT_INDEFINITELY)) {
            return null;
        }

        Date time = new Date(startMillis + (numberOfTimesExecuted * repeatInterval));

        if (endMillis <= time.getTime()) {
            return null;
        }

        return time;
    }

    /**
     * <p>
     * Returns the last time at which the <code>SimpleTrigger</code> will
     * fire, before the given time. If the trigger will not fire before the
     * given time, <code>null</code> will be returned.
     * </p>
     */
    public Date getFireTimeBefore(Date end) {
        if (end.getTime() < getStartTime().getTime()) {
            return null;
        }

        int numFires = computeNumTimesFiredBetween(getStartTime(), end);

        return new Date(getStartTime().getTime() + (numFires * repeatInterval));
    }

    public int computeNumTimesFiredBetween(Date start, Date end) {

        if(repeatInterval < 1) {
            return 0;
        }
        
        long time = end.getTime() - start.getTime();

        return (int) (time / repeatInterval);
    }

    /**
     * <p>
     * Returns the final time at which the <code>SimpleTrigger</code> will
     * fire, if repeatCount is REPEAT_INDEFINITELY, null will be returned.
     * </p>
     * 
     * <p>
     * Note that the return time may be in the past.
     * </p>
     */
    public Date getFinalFireTime() {
        if (repeatCount == 0) {
            return startTime;
        }

        if (repeatCount == REPEAT_INDEFINITELY) {
            return (getEndTime() == null) ? null : getFireTimeBefore(getEndTime()); 
        }

        long lastTrigger = startTime.getTime() + (repeatCount * repeatInterval);

        if ((getEndTime() == null) || (lastTrigger < getEndTime().getTime())) { 
            return new Date(lastTrigger);
        } else {
            return getFireTimeBefore(getEndTime());
        }
    }

    /**
     * <p>
     * Determines whether or not the <code>SimpleTrigger</code> will occur
     * again.
     * </p>
     */
    public boolean mayFireAgain() {
        return (getNextFireTime() != null);
    }

    /**
     * <p>
     * Validates whether the properties of the <code>JobDetail</code> are
     * valid for submission into a <code>Scheduler</code>.
     * 
     * @throws IllegalStateException
     *           if a required property (such as Name, Group, Class) is not
     *           set.
     */
    public void validate() throws SchedulerException {
        super.validate();

        if (repeatCount != 0 && repeatInterval < 1) {
            throw new SchedulerException("Repeat Interval cannot be zero.",
                    SchedulerException.ERR_CLIENT_ERROR);
        }
    }

    /**
     * Used by extensions of SimpleTrigger to imply that there are additional 
     * properties, specifically so that extensions can choose whether to be 
     * stored as a serialized blob, or as a flattened SimpleTrigger table. 
     */
    public boolean hasAdditionalProperties() {
        return false;
    }

    public static void main(String[] args) // TODO: remove method after good
            // unit testing
        throws Exception {

        Date sdt = new Date();

        Date edt = new Date(sdt.getTime() + 55000L);

        SimpleTrigger st = new SimpleTrigger("t", "g", "j", "g", sdt, edt, 10,
                10000L);

        System.err.println();

        st.computeFirstFireTime(null);

        System.err.println("lastTime=" + st.getFinalFireTime());

        java.util.List times = TriggerUtils.computeFireTimes(st, null, 50);

        for (int i = 0; i < times.size(); i++) {
            System.err.println("firetime = " + times.get(i));
        }
    }

}