Declare variables with the interface type

[timfox]

I've noticed quite a few places in the code where the implementation type is being used to declare variables, not the interface type, e.g.:

ArrayList myList = new ArrayList();

Yuck!, should be:

List myList = new ArrayList();

or:

MessageImpl message = new MessageImpl(JBossTextMessage.TYPE, false, 0, System.currentTimeMillis(), (byte) 1);

Should be:

Message message = new MessageImpl(JBossTextMessage.TYPE, false, 0, System.currentTimeMillis(), (byte) 1);

Please don't use the implementation type in this way, it leaks implementation details and defeats the purpose of the interface/implementation split.