Spring 3.1 Hibernate 4 exception for Inheritance [cannot be cast to org.hibernate.mapping.RootClass]

Question

Hi I have just started using Spring , with Hibernate4 and maven. Basically my class hierarchy is HUmanMicroTask extends from MicroTask . In future there may be several other classes extending from MicroTask. I was trying to have a one table per concrete class which is the simplest way to get up and running with spring3 and hibernate 4. However when i run my code. I keep getting the following exception

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 

Although I have seen quite a few forums, I am unabelt o decide on where I am making the mistake. My MicroTask class looks as follows :

@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  

My HumanMicroTask Class looks as follows :

    @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 

And my config.xml looks as follows :

<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> 

My Maven Configuration

    <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> 

Kindly help me out. I am not sure where I making the mistake.

Answer 1

It is due to Id column in both classes. Remove the Id from HumanMicroTask.