E++, an Alexandrian pattern language, describes the process for creating a J2EE framework. Compared with a loose pattern collection, E++ provides rules for design patterns to work together in solving a set of related problems. Building or migrating to an n-tier J2EE application becomes as easy as following the E++ tree network from root to leaves. Bin Yang, in this first article of two, introduces the pattern language concept and three architectural patterns, saving detailed design patterns for Part 2.