这是一个图书管理系统源代码，它应用了许多良好的设计模式，单态模式，工厂模式，享元模式，comand模式，observer模式，mvc体系结构，是学习设计模式的不错选择-This is a library management system source code, which is used by the many excellent design pattern, single-state mode the factory model, enjoy yuan model comand mode

图书管理系统，借书，还书，用到文件保存-Library management system, library, but also books, used to save the file! !

Golden section method of preparation and modulation