1

我是 Drools 的新手，正在尝试滑动窗口的概念。

我的问题是检测是否在 2 个销售事件中至少发生了一次成功的交易。即使这样的事件发生与否，我总是得到“销售已发生 2 个事件”的输出。

- - - - - - -博士升 - - - - - 

declare Sale
@role( event )
end

rule "Identify more than a single valid sale event"

//The variable saleHappened would be set to Y if a successful transaction

when sale: Sale ( saleHappened == "Y")  over window:length(2)  from entry-point MyEntryPoint

then

System.out.println("A sale has happened over 2 events" );

end

- - - - - - -代码 - - - - - 

public class DroolsTest {

    public static final void main(String[] args) {
        try {

            // load up the knowledge base 
            KnowledgeBase kbase = readKnowledgeBase(); 

            StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(); 

            WorkingMemoryEntryPoint entryPoint = ksession.getWorkingMemoryEntryPoint("MyEntryPoint");


            Sale sale = new Sale();

            sale.setSaleHappened("N");
            entryPoint.insert(sale);


            Sale sale2 = new Sale();

            sale2.setSaleHappened("N");
            entryPoint.insert(sale2);


            ksession.fireAllRules();

            ksession.dispose(); 

        } catch (Throwable t) {
            t.printStackTrace();
        }
    }


    private static KnowledgeBase readKnowledgeBase() throws Exception {

        KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder(); 
        kbuilder.add(ResourceFactory.newClassPathResource("Sample.drl"), ResourceType.DRL); 
        KnowledgeBuilderErrors errors = kbuilder.getErrors(); 
        if (errors.size() > 0) { 
                for (KnowledgeBuilderError error: errors) { 
                        System.err.println(error); 
                } 
                throw new IllegalArgumentException("Could not parse knowledge."); 
        } 

        final KnowledgeBaseConfiguration kbConfig = KnowledgeBaseFactory.newKnowledgeBaseConfiguration(); 
        kbConfig.setOption(EventProcessingOption.STREAM); 
        KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase(kbConfig); 
        kbase.addKnowledgePackages(kbuilder.getKnowledgePackages()); 
        return kbase; 
    }

    public static class Sale {

        public Sale () {

        }

        public String getSaleHappened() {
            return saleHappened;
        }

        public void setSaleHappened(String saleHappened) {
            this.saleHappened = saleHappened;
        }

        private String saleHappened;




    }

}
4

1 回答 1

2

这与错误 787118 - 长度滑动窗口保留所有事件有关。滑动窗口事件触发的概念以及事件如何不脱离窗口在 bugzilla 条目中进行了说明。

可以固定如下：

--------------drl--------------------

declare Sale
@role( event )
end

declare window Ticks
    Sale()
        over window:length( 5 )
        from entry-point MyEntryPoint
end


rule "More than 2 sale suceess in 5 events"
when     Number($cnt : intValue,intValue > 2) 
from    accumulate( Sale ( saleHappened == "Y" ) from window Ticks,  count(1) )
then
    System.out.println("A sale has happened over " + $cnt +" events" );
end
于 2012-09-19T03:17:30.517 回答