Learn how to deal with objects: creating them, reading their values and changing them, and calling their methods. Also learn how to cast objects from one class to another, cast to and from primitive data types and classes, and take advantage of automatic conversions through autoboxing and unboxing.A Primer for Aspect-Oriented Programming in Java
AOP is not a successor to OOP, but a new way of looking at object functionality: allowing the behavior of an object to be modularized and used across other components. Tim Stevens explains the difference and shows how powerful AOP can be. Perhaps too powerful.