Introducing Spring

Abstract

Over the last few years, aspect-oriented programming (AOP) has become a hot topic in the Java world, and many articles, discussions, and implementations of AOP have become available for Java programmers. AOP is often referred to as a tool for implementing crosscutting concerns, which means that you use AOP for modularizing individual pieces of logic, known as concerns, and you apply these concerns to many parts of an application. Logging and security are typical examples of crosscutting concerns that are present in many applications. Consider an application that logs the start and end of every method for debugging purposes. You will probably refactor the logging code into a special class, but you still have to call methods on that class twice per method in your application in order to perform the logging. Using AOP, you can simply specify that you want the methods on your logging class to be invoked before and after each method call in your application.