[FIXED] Reference old hibernate files from persistence.xml

Issue

I have old project that uses Hibernate 3 and I want to upgrade it and use JPA all mapping was done hbm.xml classes and not JPA annotations. Can I reference and old hbm.xml files within persistence.xml ?

Solution

Yes, you can. Look at the documentation:

Example of a persistence.xml file:

<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_2_0.xsd"
             version="2.0">
   <persistence-unit name="manager1" transaction-type="JTA">
      <provider>org.hibernate.ejb.HibernatePersistence</provider>
      <jta-data-source>java:/DefaultDS</jta-data-source>
      <mapping-file>ormap.xml</mapping-file>
      <jar-file>MyApp.jar</jar-file>
      <class>org.acme.Employee</class>
      <class>org.acme.Person</class>
      <class>org.acme.Address</class>
      <shared-cache-mode>ENABLE_SELECTOVE</shared-cache-mode>
      <validation-mode>CALLBACK</validation-mode>
      <properties>
         <property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
         <property name="hibernate.hbm2ddl.auto" value="create-drop"/>
      </properties>
   </persistence-unit>
</persistence>

You are interesting in the mapping-file element:

The class element specifies a EJB3 compliant XML mapping file that you will map. The file has to be in the classpath. As per the EJB3 specification, Hibernate EntityManager will try to load the mapping file located in the jar file at META_INF/orm.xml. Of course any explicit mapping file will be loaded too. As a matter of fact, you can provides any XML file in the mapping file element ie. either hbm files or EJB3 deployment descriptor.

Answered By - SternK