java - Drools 6 - 如何解雇规则

Question

我在 drools 6.0.1.Final 中触发简单规则时遇到问题。这是规则:

package org.drools.test
rule "test rule"
when
    eval(true)
then
    System.out.println("success");
end

这是测试代码，控制台没有输出成功。

测试 1

// Create kie file system
KieServices kieServices = KieServices.Factory.get();
KieFileSystem kfs = kieServices.newKieFileSystem();

// Add rule
Resource resource = ResourceFactory.newByteArrayResource(src.getBytes());
kfs.write("org.drools.test.testrule.drl", resource);
kieServices.newKieBuilder(kfs).buildAll();

// Create session
KieContainer kieContainer = kieServices.newKieContainer(kieServices.getRepository().getDefaultReleaseId());
KieBaseConfiguration kbaseConf = KnowledgeBaseFactory.newKnowledgeBaseConfiguration(null, RuleBaseConfiguration.class.getClassLoader());
KieBase kieBase = kieContainer.newKieBase(kbaseConf);
KieSession kieSession = kieBase.newKieSession();
kieSession.insert("Test object");

// Fire
kieSession.fireAllRules();
kieSession.dispose();

相比之下，下面的代码片段按预期运行，并且控制台输出成功。问题在于 newStatefulKnowledgeSession 方法已被弃用。据我了解，这不是 Drools 6 中的处理方式。

测试 2

Resource resource = ResourceFactory.newByteArrayResource(src.getBytes());
KnowledgeBuilder kbuilder = KnowledgeBuilderFactory.newKnowledgeBuilder();
kbuilder.add(resource, ResourceType.DRL);
StatefulKnowledgeSession ksession = kbuilder.newKnowledgeBase().newStatefulKnowledgeSession();
ksession.insert("Test object");
ksession.fireAllRules();
ksession.dispose();

调试信息

我添加了一些调试行，以尝试了解测试 1 中出了什么问题。

kieSession.addEventListener(new DebugAgendaEventListener());
kieSession.addEventListener(new DebugRuleRuntimeEventListener());

输出是:

==>[ObjectInsertedEventImpl: getFactHandle()=[fact 0:1:1784206373:1217562221:1:DEFAULT:NON_TRAIT:Test object], getObject()=Test object, getKnowledgeRuntime()=org.drools.core.impl.StatefulKnowledgeSessionImpl@4984cabc, getPropagationContext()=PhreakPropagationContext [entryPoint=EntryPoint::DEFAULT, factHandle=[fact 0:1:1784206373:1217562221:1:DEFAULT:NON_TRAIT:Test object], leftTuple=null, originOffset=-1, propagationNumber=2, rule=null, type=0]]

而在测试 2 中，输出为:

==>[ObjectInsertedEventImpl: getFactHandle()=[fact 0:1:1784206373:1217562221:1:DEFAULT:NON_TRAIT:Test object], getObject()=Test object, getKnowledgeRuntime()=org.drools.core.impl.StatefulKnowledgeSessionImpl@9738e1b, getPropagationContext()=PhreakPropagationContext [entryPoint=EntryPoint::DEFAULT, factHandle=[fact 0:1:1784206373:1217562221:1:DEFAULT:NON_TRAIT:Test object], leftTuple=null, originOffset=-1, propagationNumber=2, rule=null, type=0]]
==>[ActivationCreatedEvent: getActivation()=[[ test rule active=false ] [ null [fact 0:0:1771273200:1306428912:0:DEFAULT:NON_TRAIT:org.drools.core.reteoo.InitialFactImpl@4dde85f0] ] ], getKnowledgeRuntime()=org.drools.core.impl.StatefulKnowledgeSessionImpl@9738e1b]
==>[BeforeActivationFiredEvent:  getActivation()=[[ test rule active=false ] [ null [fact 0:0:1771273200:1306428912:0:DEFAULT:NON_TRAIT:org.drools.core.reteoo.InitialFactImpl@4dde85f0] ] ], getKnowledgeRuntime()=org.drools.core.impl.StatefulKnowledgeSessionImpl@9738e1b]
success
==>[AfterActivationFiredEvent: getActivation()=[[ test rule active=false ] [ null [fact 0:0:1771273200:1306428912:0:DEFAULT:NON_TRAIT:org.drools.core.reteoo.InitialFactImpl@4dde85f0] ] ], getKnowledgeRuntime()=org.drools.core.impl.StatefulKnowledgeSessionImpl@9738e1b]

底线

为什么测试 1 没有触发规则，而测试 2 却触发了？

Answer 1

如果直接使用KieFileSystem，则必须确保内容反射(reflect)所需的maven结构。所以，你应该写:

kfs.write("src/main/resources/org.drools.test.testrule.drl", resource);

或者，在资源上设置sourcePath并直接写入:

resource.setSourcePath( "org.drools.test.testrule.drl" );
kfs.write( resource );