Aspect-oriented software design (ASOD), which follows the Java philosophy of "write once, run anywhere", is a new way of thinking about program construction. It is a rapidly growing and evolving programming methodology that some feel may eventually replace object-orientation as the dominant programming paradigm. The first public release of the AspectJ programming language was in 1998 and has been gaining momentum ever since. This book is an introduction to AOP with AspectJ and Eclipse and shows how to create a productive AO development environment by using the AspectJ Development Tools for Eclipse (AJDT). Tools have an important role to play in learning aspect-orientation (AO) and Eclipse tools help Java developers better understand AOP. In fact the growing interest in AOP can be attributed to the better available tools and this book teaches the reader everything they need to understand AOP and apply it successfully to their own projects.