使用JPAKnowledgeService创建StatefulKnowledgeSession时发生java.lang.NullPointerException [英] java.lang.NullPointerException when creating a StatefulKnowledgeSession with JPAKnowledgeService

查看：173
本文介绍了使用JPAKnowledgeService创建StatefulKnowledgeSession时发生java.lang.NullPointerException的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

我正在尝试使JPAKnowledgeService与我的Spring Boot应用程序一起工作.为此，我遵循了这里.

I am trying to get JPAKnowledgeService work with my Spring Boot application. For this I have followed the instructions from here.

我的persistence.xml:

<?xml version="1.0" encoding="UTF-8" ?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
 http://java.sun.com/xml/ns/persistence/persistence_1_0.xsd" version="1.0">
    <persistence-unit  name="org.jbpm.persistence.jpa" transaction-type="JTA">
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
        <class>org.drools.persistence.info.SessionInfo</class>
        <class>org.drools.persistence.info.WorkItemInfo</class>
        <properties>
            <property name="hibernate.connection.url"  value="jdbc:mysql://localhost/databaseName"/>
            <property name="hibernate.connection.autocommit" value="false" />
            <property name="hibernate.jndi.class" value="bitronix.tm.jndi.BitronixInitialContextFactory"/>
            <property name="hibernate.connection.driver_class" value="com.mysql.jdbc.Driver" />
            <property name="hibernate.connection.username"  value="username"/>
            <property name="hibernate.connection.password"  value="password"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL5InnoDBDialect"/>
            <property name="hibernate.max_fetch_depth" value="3"/>
            <property name="hibernate.hbm2ddl.auto" value="update" />
            <property name="hibernate.show_sql" value="true" />
            <property name="hibernate.transaction.manager_lookup_class" value="org.hibernate.transaction.BTMTransactionManagerLookup" />
        </properties>
    </persistence-unit>
</persistence>

我还没有定义事务边界，我不得不从drools-persistence-jpa开始exclude hibernate-ja-2.0-api使用Spring本身提供的2.1.

I haven't defined transaction boundaries and I had to exclude hibernate-ja-2.0-api from drools-persistence-jpa to use 2.1 that is provided by Spring itself.

<dependency>
    <groupId>org.drools</groupId>
    <artifactId>drools-persistence-jpa</artifactId>
    <version>6.5.0.Final</version>
    <exclusions>
        <exclusion>
            <groupId>org.hibernate.javax.persistence</groupId>
            <artifactId>hibernate-jpa-2.0-api</artifactId>
        </exclusion>
    </exclusions>
</dependency>

像这样呼叫newStatefulKnowledgeSession后:

Environment env = KnowledgeBaseFactory.newEnvironment();
env.set( EnvironmentName.ENTITY_MANAGER_FACTORY, Persistence.createEntityManagerFactory( "org.jbpm.persistence.jpa" ) );
env.set( EnvironmentName.TRANSACTION_MANAGER, TransactionManagerServices.getTransactionManager() );

KieSession kSession = JPAKnowledgeService.newStatefulKnowledgeSession(kieBase, null, env);

我遇到以下错误:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'JPAKnowledgeServiceFactory' defined in class path resource [org/hasancansaral/jpaknowledgeservicesample/JPAKnowledgeServiceConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.kie.internal.runtime.StatefulKnowledgeSession]: Factory method 'JPAKnowledgeServiceFactory' threw exception; nested exception is java.lang.IllegalStateException: java.lang.reflect.InvocationTargetException
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:599) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.instantiateUsingFactoryMethod(AbstractAutowireCapableBeanFactory.java:1173) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBeanInstance(AbstractAutowireCapableBeanFactory.java:1067) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:513) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:483) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:761) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866) ~[spring-context-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542) ~[spring-context-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:762) [spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:372) [spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1187) [spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1176) [spring-boot-1.4.4.RELEASE.jar:1.4.4.RELEASE]
    at org.hasancansaral.jpaknowledgeservicesample.JPAKnowledgeServiceSample.main(JPAKnowledgeServiceSample.java:15) [classes/:na]
Caused by: org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.kie.internal.runtime.StatefulKnowledgeSession]: Factory method 'JPAKnowledgeServiceFactory' threw exception; nested exception is java.lang.IllegalStateException: java.lang.reflect.InvocationTargetException
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:189) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.beans.factory.support.ConstructorResolver.instantiateUsingFactoryMethod(ConstructorResolver.java:588) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    ... 18 common frames omitted
Caused by: java.lang.IllegalStateException: java.lang.reflect.InvocationTargetException
    at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommandService(KnowledgeStoreServiceImpl.java:185) ~[drools-persistence-jpa-6.5.0.Final.jar:6.5.0.Final]
    at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.newKieSession(KnowledgeStoreServiceImpl.java:70) ~[drools-persistence-jpa-6.5.0.Final.jar:6.5.0.Final]
    at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.newKieSession(KnowledgeStoreServiceImpl.java:39) ~[drools-persistence-jpa-6.5.0.Final.jar:6.5.0.Final]
    at org.kie.internal.persistence.jpa.JPAKnowledgeService.newStatefulKnowledgeSession(JPAKnowledgeService.java:121) ~[kie-internal-6.5.0.Final.jar:6.5.0.Final]
    at org.hasancansaral.jpaknowledgeservicesample.JPAKnowledgeServiceConfiguration.JPAKnowledgeServiceFactory(JPAKnowledgeServiceConfiguration.java:43) ~[classes/:na]
    at org.hasancansaral.jpaknowledgeservicesample.JPAKnowledgeServiceConfiguration$$EnhancerBySpringCGLIB$$a75599c4.CGLIB$JPAKnowledgeServiceFactory$0(<generated>) ~[classes/:na]
    at org.hasancansaral.jpaknowledgeservicesample.JPAKnowledgeServiceConfiguration$$EnhancerBySpringCGLIB$$a75599c4$$FastClassBySpringCGLIB$$6a4558.invoke(<generated>) ~[classes/:na]
    at org.springframework.cglib.proxy.MethodProxy.invokeSuper(MethodProxy.java:228) ~[spring-core-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassEnhancer$BeanMethodInterceptor.intercept(ConfigurationClassEnhancer.java:356) ~[spring-context-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    at org.hasancansaral.jpaknowledgeservicesample.JPAKnowledgeServiceConfiguration$$EnhancerBySpringCGLIB$$a75599c4.JPAKnowledgeServiceFactory(<generated>) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_121]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_121]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_121]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_121]
    at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:162) ~[spring-beans-4.3.6.RELEASE.jar:4.3.6.RELEASE]
    ... 19 common frames omitted
Caused by: java.lang.reflect.InvocationTargetException: null
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) ~[na:1.8.0_121]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62) ~[na:1.8.0_121]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.8.0_121]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[na:1.8.0_121]
    at org.drools.persistence.jpa.KnowledgeStoreServiceImpl.buildCommandService(KnowledgeStoreServiceImpl.java:171) ~[drools-persistence-jpa-6.5.0.Final.jar:6.5.0.Final]
    ... 33 common frames omitted
Caused by: java.lang.NullPointerException: null
    at org.drools.persistence.jta.JtaTransactionManager.getStatus(JtaTransactionManager.java:273) ~[drools-persistence-jpa-6.5.0.Final.jar:6.5.0.Final]
    at org.drools.persistence.jpa.AbstractPersistenceContextManager.getApplicationScopedEntityManager(AbstractPersistenceContextManager.java:78) ~[drools-persistence-jpa-6.5.0.Final.jar:6.5.0.Final]
    at org.drools.persistence.jpa.JpaPersistenceContextManager.getApplicationScopedPersistenceContext(JpaPersistenceContextManager.java:55) ~[drools-persistence-jpa-6.5.0.Final.jar:6.5.0.Final]
    at org.drools.persistence.SingleSessionCommandService.<init>(SingleSessionCommandService.java:103) ~[drools-persistence-jpa-6.5.0.Final.jar:6.5.0.Final]
    ... 38 common frames omitted

我也有一个示例存储库来重新创建此错误，可以在在此处找到.任何帮助是极大的赞赏.谢谢！

I also have a sample repo to recreate this error that can be found here. Any help is greatly appreciated. Thanks!

推荐答案

您需要在类路径的根目录中使用jndi.properties文件，以指向java以将bitrnix用作JNDI提供程序，以便它可以将事务管理器绑定到JNDI中，然后JtaTransactionManager可以查找

you need to use jndi.properties file in the root of your class path to point java to use bitrnix as JNDI provider so it can bind transaction manager into JNDI so then JtaTransactionManager can look it up

创建新文件:src/main/resources/jndi.properties，内容如下:

create new file: src/main/resources/jndi.properties with following content:

java.naming.factory.initial=bitronix.tm.jndi.BitronixInitialContextFactory

这篇关于使用JPAKnowledgeService创建StatefulKnowledgeSession时发生java.lang.NullPointerException的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！

查看全文
相关文章
Java开发最新文章
热门教程
热门工具
登录 关闭
扫码关注1秒登录
发送“验证码”获取 | 15天全站免登陆