[JCR-710] NullPointerException in DatabasePersistenceManager and DatabaseFileSystem after a failed reconnection attempt

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.2.1
• Fix Version/s: 1.2.2
• Component/s: jackrabbit-core
• Assignee: Stefan Guggisberg
• Reporter: Olivier Dony
• Created: 18/Jan/07 10:03
• Updated: 20/Feb/07 13:04
• Resolved: 18/Jan/07 10:59

Description

As reported on the dev mailing-list, this is what happens:

The reconnection/retry mechanism in DatabasePersistenceManager/DatabaseFileSystem seems to behave fine when the connection times out or is killed for some reason, and the DB server is in fact still running.
However there is a problem if the connection cannot be re-established directly, for example if a transient network outage lasts longer than the few reconnection attempts.
Inside DatabasePersistenceManager.reestablishConnection(), initConnection() will fail, and the preparedStatements map will stay empty.
This in turn will trigger a nasty NullPointerException (never caught) next time executeStmt() is called, because the map is still empty, and there is no check for that.

The following proposed fix from Stefan Guggisberg has been tested to work when applied on 1.2-rc2:

> the simplest fix would be to remove line 783 in
> DatabasePersistenceManager.java and line 1010 in
> DatabaseFileSystem.java,
> i.e. the following stmt:
>
> preparedStatements.clear();