CHAPTER 6

Building Domains and Services

KING ARTHUR. The Lady of the Lake, her arm clad in the purest shimmering samite held aloft Excalibur from the bosom of the water, signifying by divine providence that I, Arthur, was to carry Excalibur. THAT is why I am your king.

DENNIS, interrupting. Listen, strange women lyin' in ponds distributin' swords is no basis for a system of government. Supreme executive power derives from a mandate from the masses, not from some farcical aquatic ceremony.

Just as King Arthur and his knights embarked on a quest to find the Holy Grail in Monty Python and the Holy Grail, the next step in our discovery of Grails is to search for its very heart and soul . . . or in Java terms, its domain. Those of you familiar with Ruby on Rails and other web frameworks know the domain as a model. These synonymous terms are most often used in conjunction with the objects that are persisted against the database. Although the terms are interchangeable, for the purpose of this book, we will follow Grails' (and Java's) lead and refer to the domain.