Dangling Piyush Dangling Piyush - 1 year ago 99
Java Question

Workaround for CronSequenceGenerator Last day of month?

Ok so here it is I want to schedule a task to run on last day of every month on 10:10 AM.My cron expression is

0 10 10 L * ?

Now the problem is CronSequenceGenerator is throwing NumberFormatException for 'L' value.This means Spring's CronSequenceGenerator does'nt support this kind of expression.How to do this in any other way (workaround).I don't want to use quartz or Does spring's gonna support this in new releases.

Here is full stacktrace:

Exception in thread "main" java.lang.NumberFormatException: For input string: "L"
at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
at java.lang.Integer.parseInt(Integer.java:492)
at java.lang.Integer.valueOf(Integer.java:582)
at org.springframework.scheduling.support.CronSequenceGenerator.getRange(CronSequenceGenerator.java:324)
at org.springframework.scheduling.support.CronSequenceGenerator.setNumberHits(CronSequenceGenerator.java:297)
at org.springframework.scheduling.support.CronSequenceGenerator.setDays(CronSequenceGenerator.java:275)
at org.springframework.scheduling.support.CronSequenceGenerator.setDaysOfMonth(CronSequenceGenerator.java:266)
at org.springframework.scheduling.support.CronSequenceGenerator.parse(CronSequenceGenerator.java:239)
at org.springframework.scheduling.support.CronSequenceGenerator.<init>(CronSequenceGenerator.java:81)
at org.springframework.scheduling.support.CronTrigger.<init>(CronTrigger.java:54)
at org.springframework.scheduling.support.CronTrigger.<init>(CronTrigger.java:44)
at com.hcdc.coedp.datantar.scheduler.SchedulerUtil.start(SchedulerUtil.java:75)
at com.hcdc.coedp.datantar.scheduler.SchedulerUtil.changeTrigger(SchedulerUtil.java:106)
at com.hcdc.coedp.datantar.scheduler.SchedulingService.scheduleTransfer(SchedulingService.java:70)
at com.hcdc.coedp.datantar.scheduler.Scheduler.schedule(Scheduler.java:107)
at main.Main.main(Main.java:47)


Following is my scheduling method

* Schedule a task {@link Task} with a specified cron expression.
* @param task {@link Task}
* @param cronExpression cron expression to be applied must be a vaild one.
* @param taskName
* @return
public String start(Task task, String cronExpression, String taskName) {
CronTrigger trigger = new CronTrigger(cronExpression);//line 2

CronSequenceGenerator generator = new CronSequenceGenerator(cronExpression, TimeZone.getTimeZone("GMT+5:30"));
List<Date> dateList = new ArrayList<>(5);
Date currentDate = new Date();
for (int i = 0; i < 5; i++) {
currentDate = generator.next(currentDate);
System.out.println("Next Exceution times are" + currentDate);
ScheduledFuture sf = tps.schedule(task, trigger);

//TODO Save this scheduled future with a specific task name.
ContextHolder.schduledFutureMap.put(taskName, sf);
return cronExpression;

And on line 2 it throws NumberFormatException when I pass specified cron expression.

Answer Source

This feature is not in standard cron expression syntax. So probably Spring will never implement it. Looking at the code, I can't see any surgical solution extending CronSequenceGenerator. So why you just don't use Quartz since it's a particular feature?

Depending on your exact need, you could implement your own Trigger. Something like:

import java.util.Date;

import org.joda.time.LocalDate;
import org.joda.time.LocalTime;
import org.springframework.scheduling.Trigger;
import org.springframework.scheduling.TriggerContext;

public class LastDayOfMonthTrigger implements Trigger {

    private final LocalTime time;

    public LastDayOfMonthTrigger(LocalTime time) {
        this.time = time;

    public Date nextExecutionTime(TriggerContext ctx) {
        Date last = ctx.lastScheduledExecutionTime();
        LocalDate date = last == null ? new LocalDate() : new LocalDate(last).plusDays(1);
        LocalDate lastDay = date.dayOfMonth().withMaximumValue();
        return lastDay.toDateTime(time).toDate();