https://www.cnblogs.com/czj-zhm/p/6658564.html
http://www.cnblogs.com/zhangpengshou/p/5366413.html
https://blog.csdn.net/yangying496875002/article/details/73603303
http://wiki.jikexueyuan.com/project/intellij-idea-tutorial/interface-introduce.html
原文：https://www.cnblogs.com/kxm87/p/9160764.html