zoukankan      html  css  js  c++  java
  • Design Patterns笔记

    一些笔记。

    • strategy : facilitates the switch of the different but related algorithms/behaviors
    • observer
    • proxy : controls the access to the real subject ; shares the common interface with the real subject and sometimes provides a subset of the operations in the interface (in the case of the protection proxy)
         e.g. there are three kinds of proxies : (1) the remote proxy (surrogate the subject in the different address space); (2) the virtual proxy (SqlSessionTemplate in the mybatis.spring which is a proxy of the SqlSession); (3) the protection proxy (usually used in the os to control access to critical resouces)
    • template method : constructs the skeleton of the algorithm and leaves the variant part to be implemented by the subclasses
    • adapter : provides a uniform interface to the client which hides the different classes, usually inaccessible to clients
     
     
    TO-DO: Open-Close Principle:

    Conclusion

    Like every principle OCP is only a principle. Making a flexible design involves additional time and effort spent for it and it introduce new level of abstraction increasing the complexity of the code. So this principle should be applied in those area which are most likely to be changed.
     
    There are many design patterns that help us to extend code without changing it. For instance the Decorator pattern help us to follow Open Close principle. Also the Factory Method or the Observer pattern might be used to design an application easy to change with minimum changes in the existing code.
     
     
  • 相关阅读:
    MySQL中文显示乱码
    mysql 存储引擎 InnoDB 与 MyISAM 的区别和选择
    mysql 分表的3种方法
    mysql 清空或删除表数据后,控制表自增列值的方法
    MySQL 下优化SQL语句的一些经验
    mysql 常用命令
    MySQL获得指定数据表中auto_increment自增id值的方法及实例
    SQL Server Alwayson创建代理作业注意事项
    LinkedList子类与Queue接口
    List接口
  • 原文地址:https://www.cnblogs.com/huangzejun/p/8143805.html
Copyright © 2011-2022 走看看