Drools:时间限制规则

Question

Drools 文档提到规则可以使用date-effective和等属性date-expires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还支持使用interval as timer(int:)和cron as 定期重复的规则,timer(cron:)但这意味着规则在这些点中被触发.

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,我感兴趣.例如,让我们想象某个公司的营业时间 - 只能在正式工作期间而不是在工作时间之后执行操作.

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

是否可以将此规则延长至周一至周五上午8点至下午4点？

---

解决方案(由Esteban Aliverti提供):

Drools没有直接支持基于时间的关键字,但它们使用Quartz库提供了更强大的日历机制.StatefulSession或者WorkingMemory通过StatelessSession具有定义这些日历的方法创建,这些日历可以限制可以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:).我设法按照以下步骤执行类似于您要查找的操作:

创建会话时,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

希望能帮助到你,