摘要：
转自: https://blog.csdn.net/valada/article/details/80871698 阅读全文
摘要：
转自: https://design-patterns.readthedocs.io/zh_CN/latest/read_uml.html 参考: https://www.cnblogs.com/shindo/p/5579191.html 参考: http://www.cnblogs.com/olv 阅读全文