Defining joined-subclass in separate mapping file requires abstract parent to have a discriminator-value -------------------------------------------------------------------------------------------------------- Key: HHH-1016 URL: http://opensource.atlassian.com/projects/hibernate/browse/HHH-1016 Project: Hibernate Core Issue Type: Bug Affects Versions: 3.0 final Environment: Hibernate 3.0, MySQL 4.0.23-nt, Spring 1.2.3 Reporter: Josh Landin Priority: Minor The documentation section 6.1.15 states that "It is possible to define subclass, union-subclass, and joined-subclass mappings in separate mapping documents, directly beneath hibernate-mapping". When including a joined-subclass within the class element that it extends, a discriminator-value is not required for the abstract parent class. However, when the joined-subclass is moved into its own mapping file, the parent class element's default discriminator-value (classname) is used and consequently fails the cast to a non-string. File Parent.hbm.xml: <hibernate-mapping> <class name="com.foo.AbstractParent" table="parent" abstract="true" lazy="false"> <id name="id" type="java.lang.Long" column="entityId" unsaved-value="null"><generator class="native" /></id> <discriminator column="type" type="java.lang.Integer" not-null="true"/> <property name="name" type="java.lang.String" column="name" not-null="true" unique="true" length="100"/> </class> </hibernate-mapping> File Child.hbm.xml: <hibernate-mapping> <joined-subclass name="com.foo.Child" extends="com.foo.AbstractParent" table="child"> <key column="childId"/> <property name="status"/> </joined-subclass> </hibernate-mapping> File appctx_SessionFactory.xml (Spring): <beans> <alias alias="sessionFactory" name="org.hibernate.SessionFactory"/> <bean id="org.hibernate.SessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean"> <property name="mappingResources"> <list> <value>/com/foo/Parent.hbm.xml</value> <value>/com/foo/Child.hbm.xml</value> </list> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.cglib.use_reflection_optimizer">false</prop> <prop key="hibernate.jdbc.batch_size">0</prop> </props> </property> <property name="dataSource"> <ref bean="javax.sql.DataSource"/> </property> </bean> </beans> Causes the following when loading the mappings upon retrieving the sessionFactory from the Spring context: Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.hibernate.SessionFactory' defined in file [C:\dev\foo\classes\com\foo\common\app\resources\appctx_SessionFactory.xml]: Initialization of bean failed; nested exception is org.hibernate.MappingException: Could not format discriminator value to SQL string at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:355) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:226) at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:147) at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:269) at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:317) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:80) at org.springframework.context.support.ClassPathXmlApplicationContext.<init>(ClassPathXmlApplicationContext.java:65) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:274) at org.springframework.beans.BeanUtils.instantiateClass(BeanUtils.java:100) ... 29 more Caused by: org.hibernate.MappingException: Could not format discriminator value to SQL string at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:273) at org.hibernate.persister.PersisterFactory.createClassPersister(PersisterFactory.java:55) at org.hibernate.impl.SessionFactoryImpl.<init>(SessionFactoryImpl.java:211) at org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:1005) at org.springframework.orm.hibernate3.LocalSessionFactoryBean.newSessionFactory(LocalSessionFactoryBean.java:767) at org.springframework.orm.hibernate3.LocalSessionFactoryBean.afterPropertiesSet(LocalSessionFactoryBean.java:693) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.invokeInitMethods(AbstractAutowireCapableBeanFactory.java:1003) at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:348) ... 40 more Caused by: java.lang.NumberFormatException: For input string: "com.foo.AbstractParent" at java.lang.NumberFormatException.forInputString(NumberFormatException.java:48) at java.lang.Integer.parseInt(Integer.java:468) at java.lang.Integer.<init>(Integer.java:609) at org.hibernate.type.IntegerType.stringToObject(IntegerType.java:53) at org.hibernate.persister.entity.SingleTableEntityPersister.<init>(SingleTableEntityPersister.java:266) ... 47 more ) It seems like having (1) The parent class itself defined as abstract, and (2) The parent class mapping defined as abstract, would cause the discriminator-value to be unused. -- Josh