Over the last few years, Java 2 Platform, Enterprise Edition (J2EE) technology has emerged and matured as a standard platform for building enterprise applications. While the platform has matured into a solid offering for developing and deploying enterprise applications, it does offer its challenges. As developers, often we confuse learning the technology with learning to design with the technology. In this book, senior architects from the Sun Java Center, Sun's Java consulting organization share with the reader their cumulative design experience with and expertise on J2EE technology. The primary focus of the book is on patterns, best practices, design strategies, and proven solutions using the key J2EE technologies including JavaServer Pages (JSP), Servlets, Enterprise Java Beans (EJB), and Java Message Service (J.M.S) API. Other ancillary technologies like JDBC and JNDI are also discussed as relevant to their usage in these patterns. The J2EE Patterns catalog with 16 patterns and numerous strategies is presented to document and promote best practices for these technologies. In addition to the patterns and strategies, the book offers the following: Presents various design strategies for the presentation tier and business tier design; Identifies bad practices in presentation, business, and integration tiers, and offers directions to remedy them by using certain patterns, strategies, and refactorings; Refactorings for various tiers and mechanics to move away from a bad implementation to a better solution; Sample code and examples for patterns, strategies, and refactorings. Core J2EE Patterns delivers: Proven solutions for enterprise applications; J2EE Patterns Catalog with patterns for JSP technology, EJB technology, and J.M.S.; Identifies bad practices and recommends solutions; Refactorings to improve existing designs using patterns, strategies, and best practices; UML Diagrams illustrate structure and behavior of each pattern.