https://blog.csdn.net/ethanwalle/article/details/7488376
http://www.runoob.com/java/java-regular-expressions.html
http://baihe747.iteye.com/blog/2142710
https://blog.csdn.net/jiaobuchong/article/details/81257570
https://blog.csdn.net/CrazyMo_/article/details/67634590
https://blog.csdn.net/bingjie1217/article/details/15500069
https://blog.csdn.net/qq_26027665/article/details/79036288