Spring 3.1 Hibernate 4 的继承异常[不能转换为 org.hibernate.mapping.RootClass]

【问题标题】：Spring 3.1 Hibernate 4 exception for Inheritance [cannot be cast to org.hibernate.mapping.RootClass]Spring 3.1 Hibernate 4 的继承异常[不能转换为 org.hibernate.mapping.RootClass]
【发布时间】：2012-08-18 16:42:44
【问题描述】：

您好，我刚刚开始使用 Spring 以及 Hibernate4 和 maven。基本上我的类层次结构是 HUmanMicroTask 扩展自 MicroTask 。将来可能会有几个其他类从 MicroTask 扩展而来。我试图为每个具体类创建一个表，这是使用 spring3 和 hibernate 4 启动和运行的最简单方法。但是当我运行我的代码时。我不断收到以下异常

13:11:52,260 ERROR TestContextManager:324 - Caught exception while allowing TestExecutionListener [org.springframework.test.context.support.DependencyInjectionTestExecutionListener@6ef137d] to prepare test instance [HumanMicroTaskBaseHibernateTest@52c05d3b]
java.lang.IllegalStateException: Failed to load ApplicationContext
    at org.springframework.test.context.TestContext.getApplicationContext(TestContext.java:157)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.injectDependencies(DependencyInjectionTestExecutionListener.java:109)
    at org.springframework.test.context.support.DependencyInjectionTestExecutionListener.prepareTestInstance(DependencyInjectionTestExecutionListener.java:75)
    at org.springframework.test.context.TestContextManager.prepareTestInstance(TestContextManager.java:321)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.createTest(SpringJUnit4ClassRunner.java:211)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner$1.runReflectiveCall(SpringJUnit4ClassRunner.java:288)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.methodBlock(SpringJUnit4ClassRunner.java:290)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.runChild(SpringJUnit4ClassRunner.java:231)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
    at org.springframework.test.context.junit4.statements.RunBeforeTestClassCallbacks.evaluate(RunBeforeTestClassCallbacks.java:61)
    at org.springframework.test.context.junit4.statements.RunAfterTestClassCallbacks.evaluate(RunAfterTestClassCallbacks.java:71)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
    at org.springframework.test.context.junit4.SpringJUnit4ClassRunner.run(SpringJUnit4ClassRunner.java:174)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory' defined in class path resource [database-config.xml]: Invocation of init method failed; nested exception is java.lang.ClassCastException: org.hibernate.mapping.UnionSubclass cannot be cast to org.hibernate.mapping.RootClass
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1455)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:519)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:456)
    at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:294)
    at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:225)
    at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:291)
    at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:193)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:567)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:913)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:464)
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:103)
    at org.springframework.test.context.support.AbstractGenericContextLoader.loadContext(AbstractGenericContextLoader.java:1)
    at org.springframework.test.context.support.DelegatingSmartContextLoader.loadContext(DelegatingSmartContextLoader.java:228)
    at org.springframework.test.context.TestContext.loadApplicationContext(TestContext.java:124)
    at org.springframework.test.context.TestContext.getApplicationContext(TestContext.java:148)
    ... 24 more
Caused by: java.lang.ClassCastException: org.hibernate.mapping.UnionSubclass cannot be cast to org.hibernate.mapping.RootClass
    at org.hibernate.cfg.annotations.PropertyBinder.bind(PropertyBinder.java:212)
    at org.hibernate.cfg.annotations.PropertyBinder.makePropertyValueAndBind(PropertyBinder.java:203)
    at org.hibernate.cfg.AnnotationBinder.processElementAnnotations(AnnotationBinder.java:2013)
    at org.hibernate.cfg.AnnotationBinder.processIdPropertiesIfNotAlready(AnnotationBinder.java:768)
    at org.hibernate.cfg.AnnotationBinder.bindClass(AnnotationBinder.java:687)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processAnnotatedClassesQueue(Configuration.java:3431)
    at org.hibernate.cfg.Configuration$MetadataSourceQueue.processMetadata(Configuration.java:3385)
    at org.hibernate.cfg.Configuration.secondPassCompile(Configuration.java:1337)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1727)
    at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1778)
    at org.springframework.orm.hibernate4.LocalSessionFactoryBuilder.buildSessionFactory(LocalSessionFactoryBuilder.java:184)
    at org.springframework.orm.hibernate4.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:314)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1514)
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(AbstractAutowireCapableBeanFactory.java:1452)
    ... 38 more

虽然我看过不少论坛，但我无法确定我在哪里犯了错误。 我的 MicroTask 类如下所示：

@Entity
@Table(name = "MICROTASK")
@Inheritance(strategy = InheritanceType.TABLE_PER_CLASS)
public class MicroTask {
    @Id
    @GeneratedValue(generator = "system-uuid")
    @GenericGenerator(name = "system-uuid", strategy = "uuid")
    @Column(name = "MICROTASKID")
    private String microTaskId;
    @Column(name = "CREATIONDATE")
    private Date creationDate;
    @Column(name = "DESCRIPTION")
    private String description;

    public Date getCreationDate() {
        return creationDate;
    }
//More Getters and setters

我的 HumanMicroTask 类如下所示：

    @Entity
    @Table(name = "HUMANMICROTASK")
    @AttributeOverrides({
        @AttributeOverride(name="microTaskId", column=@Column(name="MICROTASKID")),
        @AttributeOverride(name="creationDate", column=@Column(name="CREATIONDATE")),
        @AttributeOverride(name="description", column=@Column(name="DESCRIPTION"))
    })
    public class HumanMicroTask extends MicroTask {


        @Column(name = "TITLE")
        private String title;
        @Column(name = "CHANNEL")
        private String channel;
        @Id
        @Column(name = "HMTID")
        private String humanMicroTaskid;

        public String getId() {
            return humanMicroTaskid;
        }
//More Getters and setters

我的 config.xml 如下所示：

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p"
    xmlns:context="http://www.springframework.org/schema/context" xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-3.0.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd
        ">

    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"
        destroy-method="close">
        <property name="driverClass">
            <value>${jdbc.driver.className}</value>
        </property>
        <property name="jdbcUrl">
            <value>${jdbc.url}</value>
        </property>
        <property name="user">
            <value>${jdbc.username}</value>
        </property>
        <property name="password">
            <value>${jdbc.password}</value>
        </property>

    </bean>

    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource">
            <ref bean="dataSource"/>
        </property>
        <property name="packagesToScan" value="com.hp.hpl.crowdcloud" />
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${jdbc.hibernate.dialect}</prop>
                <prop key="hibernate.hbm2ddl.auto">create</prop>
                <!-- uncomment this for first time run -->
                <prop key="hibernate.hbm2ddl.auto">create</prop>
                <prop key="hibernate.show_sql">true</prop>
            </props>
        </property>
    </bean>
    <bean id="transactionManager"
        class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <property name="sessionFactory">
            <ref bean="sessionFactory" />
        </property>
    </bean>
    <tx:annotation-driven />

</beans>

我的 Maven 配置

    <maven.test.failure.ignore>true</maven.test.failure.ignore>
    <org.springframework.version>3.1.0.RELEASE</org.springframework.version>
    <hibernate.version>4.1.1.Final</hibernate.version>
    <sl4j.version>1.5.6</sl4j.version>

请帮帮我。我不确定我在哪里犯了错误。

【问题讨论】：

标签： java spring hibernate spring-orm


【解决方案1】：

这是由于两个类中的 Id 列。从 HumanMicroTask 中删除 Id。

【讨论】：

  • 问题中的那部分代码不用删了，现在都看不懂了。
  • 成功了！谢谢你。为什么错误消息不像你的那样具有暗示性？
  • 从子类中去掉@Id注解就够了，或者你也可以删除字段，getter和setter，因为继承策略InheritanceType.TABLE_PER_CLASS要求你使用子类表中的所有继承列具有完全相同的列名，因此可以从超类继承映射。其他继承策略可能要求您为每个子实体使用不同的 ID 列名，因此 @Id 映射不能被继承到子类并显式声明。
  • 这个老了，你可能不会回答，但是如果我的子类表也有标识列呢？
  • @dhamibirendra 好吧，如果我记得我写这篇文章时的意思，那是他们自己的身份专栏。无论哪种方式，我都通过更明确的注释来整理它
【解决方案2】：

解决这个问题 从子类中删除@Id

在微任务中保持

   @Id
    @GeneratedValue(generator = "system-uuid")
    @GenericGenerator(name = "system-uuid", strategy = "uuid")
    @Column(name = "MICROTASKID")
    private String microTaskId;

在子类 HumanMicroTask 中删除

   @Id
    @Column(name = "HMTID")
    private String humanMicroTaskid;

【讨论】：

    【解决方案3】：

    前段时间我也遇到过同样的问题，因为你的父类有一个主键：'Id'，当子类生成时，它们会自动生成一个外键，其名称与父类的主键完全相同

    示例：（伪代码）

    实体定义

    父类

      @Entity
    @Inheritance(strategy = InheritanceType.JOINED)
    @Table(name = "abstract_person", catalog = "catalog", schema = "")
    class AbstractPerson{

        //Primary Key
        @Id
        @Column(name = "idPerson")
        int idPerson;

        @Basic
        @Column(name = "name")
        String name;

        //corresponding getters and setters
    }

    儿童班：

     @Entity
    @Table(name = "concrete_person", catalog = "catalog", schema = "")
    class ConcretePerson extends AbstractPerson{

       //No id or primary key is defined here

        @Basic
        @Column(name="profession")
        String profession;

    }

    表生成

    父类会映射到这个

    表格“abstract_person”
    id: Int (主键)
    名称：Varchar

    子类将映射到这个：


    表格“concrete_person”
    职业：Varchar
    idPerson: int (自动生成，父表和主表的外键 该表的类）

    //假设
    Mysql数据库；
    Jpa 2 Hibernate 实现；
    NetBeans 7x 创意

    【讨论】：

      【解决方案4】：

      对于 TABLE_PER_CLASS 层次结构，子类从父类继承唯一键，因此我们不应在子实体中提及唯一键约束。

      删除主键注释，这对我来说效果很好。

      【讨论】：

        猜你喜欢
        • 1970-01-01
        • 1970-01-01
        • 2016-12-02
        • 1970-01-01
        • 1970-01-01
        • 2012-03-12
        • 1970-01-01
        • 2021-10-24
        相关资源
        最近更新 更多
        热门标签
        Java Python linux javascript Mysql C# Docker 算法 前端 SpringBoot Redis Vue spring 设计模式 .net core .net kubernetes c++ 数据库 数据结构 大数据 js 机器学习 微服务 Android Go 程序员 面试 JVM ASP.net core 云原生 人工智能 后端 PHP git CSS golang k8s Nginx Django mybatis 深度学习 多线程 React 架构 devops 爬虫 云计算 Spring Boot LeetCode