This shows a JPA configuration for inheritance. There are three different types, which are single table, joined, and table per class.
This example uses joined inheritance. Joined inheritance involves a base table for shared fields and a table for each
subclass. There is a Person class that is the parent for Student and Professional.
This example is based on One to Many JPA Hibernate Configuration, but
has been modified enough to add inheritance.
The Person DAO is configured using context:component-scan. Then tx:annotation-driven will configure transactions
on any beans with @Transactional, and just after it the JPA transaction manager is setup.
The jdbc:embedded-database element is used to initialize the test HSQLDB database.
The LocalContainerEntityManagerFactoryBean is configured with the DataSource and for use with Hibernate as the JPA adapter.
The persistenceUnitName attribute is set to specify which persistence unit to use (multiple examples use the persistence.xml).
<?xml version="1.0" encoding="UTF-8"?>
<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:jdbc="http://www.springframework.org/schema/jdbc"
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/context
http://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/jdbc
http://www.springframework.org/schema/jdbc/spring-jdbc.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<context:component-scan base-package="org.springbyexample.orm.jpa.inheritance.dao" />
<tx:annotation-driven />
<bean id="transactionManager"
class="org.springframework.orm.jpa.JpaTransactionManager"
p:entityManagerFactory-ref="entityManagerFactory"/>
<jdbc:embedded-database id="dataSource" type="HSQL">
<jdbc:script location="classpath:/schema_inheritance.sql" encoding="UTF-8" />
</jdbc:embedded-database>
<bean id="entityManagerFactory"
class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean"
p:dataSource-ref="dataSource"
p:persistenceUnitName="inheritance-jpa">
<property name="jpaVendorAdapter">
<bean class="org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter" />
</property>
</bean>
</beans>