文件名称：Spring 2.5 Aspect-Oriented Programming
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更新时间：2012-09-23 13:09:43
spring aop 2.5
In software engineering, mostly low-level languages were used for many years, which were closer to the computer machine code than to human language. In the 70s, Brian Kernighan and Dennis Ritchie created the language C. It was quite similar to human language, making it easier and faster to write code, while keeping a high level of abstraction. This allowed the realization of concepts and ideas, which was not possible for the previous languages as they were forced to focus on the processor's language. Later, Smalltalk and C++ permitted the shaping of concepts and ideas through objects‚ providing a new way to structure applications and write programs. With the object-oriented languages, any system could be created with increasing complexity in a more manageable way, thanks to the modeling of entities in the form of types and the collaboration between them. In some cases, object-oriented programming introduces or causes inefficiencies, and aspect-oriented programming helps in filling these gaps. The aim of Aspect-Oriented Programming (AOP) is not to replace Object-Oriented Programming (OOP), but to complement it, allowing you to create clearer and better structured programs. Gregor Kiczales, one of the founders of AOP, said (an extract from http://www.cs.ubc.ca/~gregor/papers/kiczales-ECOOP1997-AOP.pdf) "We have found many programming problems for which neither procedural nor object-oriented programming techniques are sufficient to clearly capture some of the important design decisions the program must implement. This forces the implementation of those design decisions to be scattered throughout the code, resulting in tangled code that is excessively difficult to develop and maintain." Neither aspect-oriented programming nor object-oriented programming can make up for a bad design: The first assumption is that a software system is well-designed. There is no solution for a badly designed system, and also none for a badly implemented system. There is only one good strategy: to change it. The difference between a good and a bad design is the capacity to evolve and adapt to new requirements without being twisted. Object-oriented programming, supported by aspect-oriented programming, helps designers and developers in this direction. This material is copyright and is licensed for the sole use by Richard Ostheimer on 6th June 2009 2205 hilda ave., , missoula, , 59801