runoob
http://www.runoob.com/design-pattern/design-pattern-tutorial.html
w3cschool.
https://www.w3cschool.cn/javadesignpattern/
https://www.w3cschool.cn/shejimoshi/
runoob
http://www.runoob.com/design-pattern/design-pattern-tutorial.html
w3cschool.
https://www.w3cschool.cn/javadesignpattern/
https://www.w3cschool.cn/shejimoshi/