CronSequenceGenerator的解决方法一月中的最后一天？ [英] Workaround for CronSequenceGenerator Last day of month?

问题描述

好的，所以这里是我想计划任务在每月的最后一天上午10:10运行。cron表达式是

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 * ?

现在问题是 CronSequenceGenerator 抛出NumberFormatException为'L'值。这意味着Spring的CronSequenceGenerator不支持这种表达式。如何做任何其他方式（解决方法）。我不想使用石英或春天的支持这个在新的版本。

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.

这里是完整的stacktrace：

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)

更新：

以下是我的计划方法

 /**
    * 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);
            dateList.add((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;
    }

在第2行，当我传递指定的cron表达式时会抛出NumberFormatException。 p>

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

推荐答案

此功能不在标准cron表达式语法。所以大概Spring将永远不会实现它。查看代码，我看不到任何扩展 CronSequenceGenerator 的手术解决方案。那么为什么你不使用Quartz，因为它是一个特定功能？

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?

根据您的确切需要，您可以实施您自己的触发。像：

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;
    }

    @Override
    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();
    }
}

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