Java dynamic article

A good series at IBM
http://www.ibm.com/developerworks/java/library/j-dyn0916.html

Excellent class loader article

http://www.javaworld.com/javaworld/javaqa/2003-07/02-qa-0725-classsrc2.html?page=3

Can show all classes loaded and all class loaders.

Grails database transaction

This is my experience so far.

If transactional is set to true, Grails will always do a real commit when the public method exits. Even using save(flush:true), it won't commit to database until method exits.

Using withTransaction to scope block of code for which you want to commit it when block ends. But be sure to change transactional to false. I think transactional=true will override withTransaction, i.e. it will still try to commit when the method exits.