drools - Drools Fusion CEP 中的测试事件到期

Question

Ciao，我已经测试了几种方法，但我仍然无法在Drools Fusion中测试和验证事件过期机制，所以我正在寻找一些指导，好吗？

我已经阅读了手册，我对这个功能很感兴趣:

In other words, one an event is inserted into the working memory, it is possible for the engine to find out when an event can no longer match other facts and automatically retract it, releasing its associated resources.

我在 Eclipse 中使用 Drools IDE，5.4.0.Final 并且我修改了由“New Drools Project”向导创建的模板代码来测试和验证事件过期。

下面的代码。我理解的使“生命周期”正常工作的方式是:

您必须在 STREAM 模式下设置 KBase - 检查

您必须按时间顺序插入事件 - 检查

您必须在事件之间定义时间约束 - 在我的情况下检查是 last Message()

但是，当我最后检查 EventFactHandle 时，没有一个 Event() 已过期。
感谢您的帮助。

java :

public class DroolsTest {

    public static final void main(String[] args) {
        try {
            KnowledgeBase kbase = readKnowledgeBase();
            // I do want the pseudo clock
            KnowledgeSessionConfiguration conf = KnowledgeBaseFactory.newKnowledgeSessionConfiguration();
            conf.setOption(ClockTypeOption.get("pseudo"));
            StatefulKnowledgeSession ksession = kbase.newStatefulKnowledgeSession(conf, null);
            SessionPseudoClock clock = ksession.getSessionClock();
            KnowledgeRuntimeLogger logger = KnowledgeRuntimeLoggerFactory.newFileLogger(ksession, "test");
            // Insert of 2 Event:
            Message message = new Message();
            message.setMessage("Message 1");
            message.setStatus(Message.HELLO);
            ksession.insert(message);
            ksession.fireAllRules();
            clock.advanceTime(1, TimeUnit.DAYS);
            Message message2 = new Message();
            message2.setMessage("Message 2");
            message2.setStatus(Message.HELLO);
            ksession.insert(message2);
            ksession.fireAllRules();
            clock.advanceTime(1, TimeUnit.DAYS);
            ksession.fireAllRules();
            // Now I do check what I have in the working memory and if EventFactHandle if it's expired or not:
            for (FactHandle f : ksession.getFactHandles()) {
                if (f instanceof EventFactHandle) {
                    System.out.println(((EventFactHandle)f)+" "+((EventFactHandle)f).isExpired());
                } else {
                    System.out.println("not an Event: "+f);
                }
            }
            logger.close();
        } 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.");
        }
        KnowledgeBase kbase = KnowledgeBaseFactory.newKnowledgeBase();
        kbase.addKnowledgePackages(kbuilder.getKnowledgePackages());
        // following 2 lines is the template code modified for STREAM configuration
        KnowledgeBaseConfiguration config = KnowledgeBaseFactory.newKnowledgeBaseConfiguration();
        config.setOption( EventProcessingOption.STREAM );
        return kbase;
    }

    /*
     * This is OK from template, as from the doc:
     * By default, the timestamp for a given event is read from the Session Clock and assigned to the event at the time the event is inserted into the working memory.
     */
    public static class Message {

        public static final int HELLO = 0;
        public static final int GOODBYE = 1;

        private String message;

        private int status;

        public String getMessage() {
            return this.message;
        }

        public void setMessage(String message) {
            this.message = message;
        }

        public int getStatus() {
            return this.status;
        }

        public void setStatus(int status) {
            this.status = status;
        }

    }

}

流口水:

package com.sample

import com.sample.DroolsTest.Message;

declare Message
@role(event)
end

declare window LastMessageWindow
    Message() over window:length(1)
end

rule "Hello World"
    when
       accumulate( $m : Message(status==Message.HELLO) from window LastMessageWindow,
                $messages : collectList( $m ) )
    then
        System.out.println( ((Message)$messages.get(0)).getMessage() );
end

请注意:即使我在 Message 事件中添加了 1 秒的过期时间，通过

@expires(1s)

我仍然没有得到插入的第一个 Message 事件的预期结果，我原以为现在已经过期？感谢您的帮助。

Answer 1

找到解决方案!显然是我愚蠢，没有意识到我在使用 Drools 5.4.0.Final，同时仍然引用 5.2.0.Final 的旧文档。在 Drools Fusion 5.4.0.Final 的更新文档中，为 添加了此框2.6.2.滑动长度窗 :

Please note that length based windows do not define temporal constraints for event expiration from the session, and the engine will not consider them. If events have no other rules defining temporal constraints and no explicit expiration policy, the engine will keep them in the session indefinitely.

因此，我最初提出的“您必须在事件之间定义时间约束”的第三个要求显然没有得到满足，因为我现在了解 Drools 5.4.0.Final 中的滑动长度窗口:

Message() over window:length(1)

确实不是 session 中事件到期的时间约束的定义。

更新这个答案希望有人会发现它有帮助。另外，就您所知，我实际上是愚蠢的，因为我依靠谷歌搜索来访问文档，有时您没有被重定向到当前的发布文档，所以看起来......