JBoss-Hibernate Integration (Switching Hibernate Versions)

- Steve Ebersole, JBoss Inc

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Within JBossAS, all Hibernate version-2 vs. version-3

dependencies are isolated to the deploy/jboss-hibernate.deployer

archive (exploded by default).  In general, switching between

Hibernate2-based integration and Hibernate3-based integration

is as simple as dropping in the appropriate version of the

jboss-hibernate.deployer.

Note that if you are planning on using the Hibernate3-based

integration for an application initially developed to use

Hibernate2, make sure you understand the implications of a

migration from Hibernate2 to Hibernate3.  Be sure to read

the migration guide

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Switching from Hibernate3 to Hibernate2

This should mainly be users of JBossAS 4.0.2 and later (or

perhaps users reversing a previous switch from Hibernate2 to

Hibernate3), wanting to use Hibernate2 instead of Hibernate3.

Simply delete the existing deploy/jboss-hibernate.deployer from

your system and drop in the Hibernate2-based jboss-hibernate.deployer.

The Hibernate2-based deployer archive is contained within the attached

file named hibernate2-deployer.zip.  Note that this version bundles

Hibernate version 2.1.8, and is based on JBoss version 4.0.2RC1.

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Switching from Hibernate2 to Hibernate3

This should mainly be users of JBossAS 4.x prior to 4.0.2 (or

perhaps users reversing a previous switch from Hibernate2 to

Hibernate3 in JBossAS version 4.0.2 and later) who want to upgrade to use Hibernate3 but not upgrade to JBossAS 4.0.2 or higher.

Again, simply delete the existing deploy/jboss-hibernate.deployer from

your system and drop in the Hibernate3-based jboss-hibernate.deployer.

The Hibernate3-based deployer archive is contained within the attached

file named hibernate3-deployer.zip.  Note that this version bundles

Hibernate version 3.0.3.

An even better choice, here, is to obtain the JBoss source,build the

hibernate module, and use the resulting jboss-hibernate.deployer

archive for your drop-in as that will give you the most up-to-date

version.

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Using Hibernate3 to Hibernate2 Simultaneously

Using the integration for both Hibernate2 and Hibernate3 simultaneously

is a bit more complicated.  You need to make certain you are using the deployer-less versions of both the Hibernate2 and Hibernate3 integration modules.  The deployer-less code for Hibernate3 is the source currently in JBoss CVS.  The source for Hibernate2 deployer-less integration is attached below as hibernate2-no-deployer-src.zip (see the docs for the Hibernate3 deployer-less integration as the attached functions in a similiar fashion).  The attached package additionally renames the package to org.jboss.hibernate2... to avoid namespace issues.

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