The Magician's Code

A monk of the Elephant's Footprint Clan found that his new service method was failing to update the database, although no exceptions were thrown. He sought the help of Java master Bawan.

After a brief investigation, Bawan declared, “Your Service’s auto-generated proxy object is not committing the transaction because the Transactional annotation was placed on a private helper method, instead of on the public interface method which calls it.”

“I do not understand,” said the monk. “What is this ‘proxy object’ that you speak of?”

Bawan eyed the monk suspiciously. “Describe to me how commits and rollbacks are done by the AOP framework.”

The monk shrugged. “They are done automatically.”

Bawan smacked the monk on the head. “If I ask you how the Emperor’s magician makes rabbits disappear, will you answer: ‘by magic’? Think before speaking, or I will show you how I make monks disappear.”

The monk rubbed his head. “Should we not expect a third-party framework to liberate us from the need to know its internals? What of the Principle of the Black Box?”

Bawan reached behind the monk’s left ear, produced a wooden spoon out of thin air, and hit the monk with that too. “When a rabbit is placed inside the Black Box and vanishes on cue, it is the audience’s privilege to simply ooh and aah in wonderment. But we who step on stage should know how the trick is done. The loss of innocence is the price of applause.”