[JCR-2578] Deprecate XASession

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 2.2
• Component/s: jackrabbit-api, jackrabbit-core, jackrabbit-jca, transactions
• Assignee: Jukka Zitting
• Reporter: Jukka Zitting
• Created: 19/Mar/10 13:39
• Updated: 08/Nov/11 15:52
• Resolved: 13/Apr/10 11:17

Description

The XASession interface in jackrabbit-api extends Session with a single getXAResource() method. The idea is that a transactional client (or a transaction manager) will test whether a session implements XASession and can then get the XAResource instance that can be used to bind the session to a distributed transaction. The essential code is:

if (session instanceof XASession)

{ return ((XASession) session).getXAResource(); }

This works fine except for the extra dependency to jackrabbit-api that it introduces in code that otherwise would only need the JCR API. Since the link between a transaction-enabled session and the related XAResource instance is always one-to-one, we could avoid this dependency by making the session directly implement XAResource, leading to code like this:

if (session instanceof XAResource)

{ return (XAResource) session; }

This is essentially what jackrabbit-jcr-rmi did in 2.0.0 to avoid the jackrabbit-api dependency while maintaining XA transaction support, and I'd like to extend this solution also to other parts of Jackrabbit.