java - 流口水:限时规则

Question

流口水 documentation提到规则可以使用 date-effective 和 date-expires 等属性来指定绝对规则有效期。

例如

rule "Date-restricted rule"
    date-effective "20.2.2013 8:00"      # 8 AM
    date-expires   "20.2.2013 16:00"     # 4 PM
    when
    then
end

Drools 还支持周期性重复的规则，间隔为 timer(int:) 和 cron 为 timer(cron:) 但这意味着规则在这些点被触发.

问题:

如果有任何选项如何指定具有时间限制的定期可用(未触发)规则，我很感兴趣。例如，让我们想象一下某公司的营业时间——该操作只能在正式工作期间执行，而不能在下类后执行。

我想要这样的东西，但这不是 Drools 的有效规则

rule "Time-restricted rule"
    time-effective "8:00"      # 8 AM
    time-expires   "16:00"     # 4 PM
    when
    then
end

是否可以将此类规则扩展为仅在周一至周五上午 8 点至下午 4 点生效？

---

解决方案(由 Esteban Aliverti 提供):

Drools 不直接支持基于时间的关键字，但它们使用 Quartz 提供了更强大的日历机制。图书馆。由 StatelessSession 创建的 StatefulSession 或 WorkingMemory 具有定义这些日历的方法，这些日历可以限制触发规则的日期和时间。

示例:规则定义

rule "Business hours only"
    calendars "business-hours"
    when
        SomeAttachedClass()
    then
        System.out.println("Rule is fired");
end

日历定义

import org.quartz.impl.calendar.DailyCalendar;

// stateless session and working memory or directly stateful session
StatefulKnowledgeSession memory = session.newWorkingMemory(); 
// interested time range is 8-16, also there is many Calendar implementation, not just Daily
DailyCalendar businessHours = new DailyCalendar( 8, 0, 0, 0, 16, 0, 0, 0 );
// by default, defined time is EXCLUDED, the inversion makes it INCLUDED and excludes the rest
businessHours.setInvertTimeRange( true );
//convert the calendar into a org.drools.time.Calendar
org.drools.time.Calendar businessHoursCalendar = QuartzHelper.quartzCalendarAdapter( businessHours );
//Register the calendar in the session with a name. You must use this name in your rules.
memory.getCalendars().set( "business-hours", businessHoursCalendar );

Answer 1

更好的方法是使用 calendar 而不是 timer(cron:)。我按照以下步骤设法做了与您正在寻找的类似的事情:

创建 session 时，您必须创建和配置 Quartz 日历:

//in this case I'm using a DailyCalendar but you can use whatever implementation of Calendar you want
org.quartz.impl.calendar.DailyCalendar businessHours = new org.quartz.impl.calendar.DailyCalendar("business-hours", 8, 0, 0, 0, 16, 0, 0, 0);
businessHours.setInvertTimeRange(true);

//convert the calendar into a org.drools.time.Calendar
org.drools.time.Calendar businessHoursCalendar = QuartzHelper.quartzCalendarAdapter(businessHours);

//Register the calendar in the session with a name. You must use this name in your rules.
ksession.getCalendars().set( "business-hours", businessHoursCalendar );

然后在你的规则中你必须写这样的东西:

rule "Rule X"
    calendars "business-hours"
when
    ...
then
    ...
end

希望对你有帮助