开源规则引擎 Drools 学习笔记 之 -- 1 cannot be cast to org.drools.compiler.kie.builder.impl.InternalKieModule

  • 作者: 凯哥Java(公众号:凯哥Java)
  • Drools
  • 时间:2021-07-15 15:00
  • 5339人已阅读
简介 直接进入正题我们在使用开源规则引擎 Drools 的时候,启动的时候可能会抛出如下异常:java.lang.IllegalStateException: Failed to load ApplicationContextat org.springframework.test.context.cache.DefaultCacheA

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直接进入正题

我们在使用开源规则引擎 Drools 的时候, 启动的时候可能会抛出如下异常:

35451fe97e4529f94e8152e84e98f1c5.png

java.lang.IllegalStateException: Failed to load ApplicationContext

	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:132)
	at org.springframework.test.context.support.DefaultTestContext.getApplicationContext(DefaultTestContext.java:124)
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:118)
	at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:83)
	at org.springframework.boot.test.autoconfigure.SpringBootDependencyInjectionTestExecutionListener.prepareTestInstance(SpringBootDependencyInjectionTestExecutionListener.java:43)
	at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:244)
	at org.springframework.test.context.junit.jupiter.SpringExtension.postProcessTestInstance(SpringExtension.java:138)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$invokeTestInstancePostProcessors$6(ClassBasedTestDescriptor.java:350)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.executeAndMaskThrowable(ClassBasedTestDescriptor.java:355)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$invokeTestInstancePostProcessors$7(ClassBasedTestDescriptor.java:350)
	at java.util.stream.ReferencePipeline$3$1.accept(ReferencePipeline.java:193)
	at java.util.stream.ReferencePipeline$2$1.accept(ReferencePipeline.java:175)
	at java.util.ArrayList$ArrayListSpliterator.forEachRemaining(ArrayList.java:1374)
	at java.util.stream.AbstractPipeline.copyInto(AbstractPipeline.java:481)
	at java.util.stream.AbstractPipeline.wrapAndCopyInto(AbstractPipeline.java:471)
	at java.util.stream.StreamSpliterators$WrappingSpliterator.forEachRemaining(StreamSpliterators.java:312)
	at java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:743)
	at java.util.stream.Streams$ConcatSpliterator.forEachRemaining(Streams.java:742)
	at java.util.stream.ReferencePipeline$Head.forEach(ReferencePipeline.java:580)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.invokeTestInstancePostProcessors(ClassBasedTestDescriptor.java:349)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$instantiateAndPostProcessTestInstance$4(ClassBasedTestDescriptor.java:270)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.instantiateAndPostProcessTestInstance(ClassBasedTestDescriptor.java:269)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$testInstancesProvider$2(ClassBasedTestDescriptor.java:259)
	at java.util.Optional.orElseGet(Optional.java:267)
	at org.junit.jupiter.engine.descriptor.ClassBasedTestDescriptor.lambda$testInstancesProvider$3(ClassBasedTestDescriptor.java:258)
	at org.junit.jupiter.engine.execution.TestInstancesProvider.getTestInstances(TestInstancesProvider.java:31)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.lambda$prepare$0(TestMethodTestDescriptor.java:101)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:100)
	at org.junit.jupiter.engine.descriptor.TestMethodTestDescriptor.prepare(TestMethodTestDescriptor.java:65)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$prepare$1(NodeTestTask.java:111)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.prepare(NodeTestTask.java:111)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:79)
	at java.util.ArrayList.forEach(ArrayList.java:1249)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
	at java.util.ArrayList.forEach(ArrayList.java:1249)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.invokeAll(SameThreadHierarchicalTestExecutorService.java:38)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$5(NodeTestTask.java:143)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$7(NodeTestTask.java:129)
	at org.junit.platform.engine.support.hierarchical.Node.around(Node.java:137)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.lambda$executeRecursively$8(NodeTestTask.java:127)
	at org.junit.platform.engine.support.hierarchical.ThrowableCollector.execute(ThrowableCollector.java:73)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.executeRecursively(NodeTestTask.java:126)
	at org.junit.platform.engine.support.hierarchical.NodeTestTask.execute(NodeTestTask.java:84)
	at org.junit.platform.engine.support.hierarchical.SameThreadHierarchicalTestExecutorService.submit(SameThreadHierarchicalTestExecutorService.java:32)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestExecutor.execute(HierarchicalTestExecutor.java:57)
	at org.junit.platform.engine.support.hierarchical.HierarchicalTestEngine.execute(HierarchicalTestEngine.java:51)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:108)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:88)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.lambda$execute$0(EngineExecutionOrchestrator.java:54)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.withInterceptedStreams(EngineExecutionOrchestrator.java:67)
	at org.junit.platform.launcher.core.EngineExecutionOrchestrator.execute(EngineExecutionOrchestrator.java:52)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:96)
	at org.junit.platform.launcher.core.DefaultLauncher.execute(DefaultLauncher.java:75)
	at com.intellij.junit5.JUnit5IdeaTestRunner.startRunnerWithArgs(JUnit5IdeaTestRunner.java:71)
	at com.intellij.rt.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:33)
	at com.intellij.rt.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:220)
	at com.intellij.rt.junit.JUnitStarter.main(JUnitStarter.java:53)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'kieContainer' defined in class path resource [com/example/drools/droolsdemo/config/DroolsAutoConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.kie.api.runtime.KieContainer]: Factory method 'kieContainer' threw exception; nested exception is java.lang.ClassCastException: com.example.drools.droolsdemo.config.DroolsAutoConfiguration$$Lambda$701/1083803390 cannot be cast to org.drools.compiler.kie.builder.impl.InternalKieModule
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:658)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:486)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1334)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1177)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:564)
	at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:524)
	at org.springframework.beans.factory.support.AbstractBeanFactory.lambda$doGetBean$0(AbstractBeanFactory.java:335)
	at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:234)
	at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:333)
	at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:208)
	at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:944)
	at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:918)
	at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:583)
	at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:758)
	at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:438)
	at org.springframework.boot.SpringApplication.run(SpringApplication.java:337)
	at org.springframework.boot.test.context.SpringBootContextLoader.loadContext(SpringBootContextLoader.java:123)
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContextInternal(DefaultCacheAwareContextLoaderDelegate.java:99)
	at org.springframework.test.context.cache.DefaultCacheAwareContextLoaderDelegate.loadContext(DefaultCacheAwareContextLoaderDelegate.java:124)
	... 68 more
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.kie.api.runtime.KieContainer]: Factory method 'kieContainer' threw exception; nested exception is java.lang.ClassCastException: com.example.drools.droolsdemo.config.DroolsAutoConfiguration$$Lambda$701/1083803390 cannot be cast to org.drools.compiler.kie.builder.impl.InternalKieModule
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:185)
	at org.springframework.beans.factory.support.ConstructorResolver.instantiate(ConstructorResolver.java:653)
	... 86 more
Caused by: java.lang.ClassCastException: com.example.drools.droolsdemo.config.DroolsAutoConfiguration$$Lambda$701/1083803390 cannot be cast to org.drools.compiler.kie.builder.impl.InternalKieModule
	at org.drools.compiler.kie.builder.impl.KieServicesImpl.newKieContainer(KieServicesImpl.java:188)
	at org.drools.compiler.kie.builder.impl.KieServicesImpl.newKieContainer(KieServicesImpl.java:176)
	at com.example.drools.droolsdemo.config.DroolsAutoConfiguration.kieContainer(DroolsAutoConfiguration.java:48)
	at com.example.drools.droolsdemo.config.DroolsAutoConfiguration$$EnhancerBySpringCGLIB$$1626d42.CGLIB$kieContainer$3(<generated>)
	at com.example.drools.droolsdemo.config.DroolsAutoConfiguration$$EnhancerBySpringCGLIB$$1626d42$$FastClassBySpringCGLIB$$af4cd174.invoke(<generated>)
	at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:244)
	at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:331)
	at com.example.drools.droolsdemo.config.DroolsAutoConfiguration$$EnhancerBySpringCGLIB$$1626d42.kieContainer(<generated>)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:498)
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154)
	... 87 more

发现是DroolsAutoConfiguration类里面异常了。

package com.example.drools.droolsdemo.config;

import org.kie.api.KieBase;
import org.kie.api.KieServices;
import org.kie.api.builder.KieBuilder;
import org.kie.api.builder.KieFileSystem;
import org.kie.api.builder.KieRepository;
import org.kie.api.runtime.KieContainer;
import org.kie.api.runtime.KieSession;
import org.kie.internal.io.ResourceFactory;
import org.kie.spring.KModuleBeanFactoryPostProcessor;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;
import org.springframework.core.io.support.PathMatchingResourcePatternResolver;
import org.springframework.core.io.support.ResourcePatternResolver;

import java.io.IOException;

@Configuration
public class DroolsAutoConfiguration {

    private static final String RULES_PATH = "rules/";

    @Bean
    @ConditionalOnMissingBean(KieFileSystem.class)
    public KieFileSystem kieFileSystem() throws IOException {
        KieFileSystem kieFileSystem = getKieServices().newKieFileSystem();
        for (Resource file : getRuleFiles()) {
            kieFileSystem.write(ResourceFactory.newClassPathResource(RULES_PATH + file.getFilename(), "UTF-8"));
        }
        return kieFileSystem;
    }

    private Resource[] getRuleFiles() throws IOException {
        ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
        return resourcePatternResolver.getResources("classpath*:" + RULES_PATH + "**/*.*");
    }

    @Bean
    @ConditionalOnMissingBean(KieContainer.class)
    public KieContainer kieContainer() throws IOException {
        final KieRepository kieRepository = getKieServices().getRepository();
        kieRepository.addKieModule(kieRepository::getDefaultReleaseId);
        KieBuilder kieBuilder = getKieServices().newKieBuilder(kieFileSystem());
        kieBuilder.buildAll();
        return getKieServices().newKieContainer(kieRepository.getDefaultReleaseId());
    }

    private KieServices getKieServices() {
        return KieServices.Factory.get();
    }

    @Bean
    @ConditionalOnMissingBean(KieBase.class)
    public KieBase kieBase() throws IOException {
        return kieContainer().getKieBase();
    }

    @Bean
    @ConditionalOnMissingBean(KieSession.class)
    public KieSession kieSession() throws IOException {
        KieSession kieSession = kieContainer().newKieSession();
        return kieSession;
    }

    @Bean
    @ConditionalOnMissingBean(KModuleBeanFactoryPostProcessor.class)
    public KModuleBeanFactoryPostProcessor kiePostProcessor() {
        return new KModuleBeanFactoryPostProcessor();
    }
}

此为初始化 drl 文件时的异常, 说明我们的 drl 文件不规范, Drools 不能解析成功.


我仔细检查了一下:

rule "read-Reading-speed"
when
    $rlt:ReadingLevelTest(totalWordsNum != null,totalSecondTime != null)
    $rl:ReadingLevel(readingSpeed == null)
then
    $rl.setReadingSpeed($rlt.getTotalWordsNum()/$rlt.getTotalSecondTime()/60);
    update($rl)
    System.out.println("测评结果读速: " + $rl.toString());
 end

发现其实是因为在 then 中的 update($rl) 后没有用分号结尾, 加上分号运行正常.

  • when 后面每行表达式后面是不需要添加分号结尾的

  • then 后面为 java 代码, 每行必须使用分号结尾, 如果我们忘记了添加分号,编译器也会报错题型的, 但是有一些特例, 比如 Drools 提供的方法 update(),insert 等等, 如果后面不加分号, 编译器是不会报错的, 但是运行的时候就会抛出解析失败!

原因二:

import的类被我删除了。

2ff179a92d19ff7c6e9ac9b1debf4363.png

解决:

删除到错误引用就可以了。

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