3.2.2.7. Migrate Your Hibernate 3.5.x Application to Hibernate 4.x

Procedure 3.15. 

1. Merge the AnnotationConfiguration into the Configuration

   Although AnnotationConfiguration is now deprecated, it should not affect your migration.
   If you are still using an hbm.xml file, you should be aware that JBoss Enterprise Application Platform 6 now uses the org.hibernate.cfg.EJB3NamingStrategy in AnnotationConfiguration instead of the org.hibernate.cfg.DefaultNamingStrategy that was used in previous releases. This can result in naming mismatches. If you rely on the naming strategy to default the name of an association (many-to-many and collections of elements) table, you may see this issue. To resolve it, you can tell Hibernate to use the legacy org.hibernate.cfg.DefaultNamingStrategy by calling Configuration#setNamingStrategy and passing it org.hibernate.cfg.DefaultNamingStrategy#INSTANCE.

2. Modify the namespaces to conform to the new Hibernate DTD file names.

   Table 3.5. 

   Previous DTD Namespace	New DTD Namespace
   http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd	http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd
   http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd	http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd

3. Modify environment variables

   1. If you are using Oracle and using the materialized_clob or materialized_blob properties, the global environment variable hibernate.jdbc.use_streams_for_binary must be set to true.
   2. If you are using PostgreSQL and using the CLOB or BLOB properties, the global environment variable hibernate.jdbc.use_streams_for_binary must be set to false.