mybatis 优雅使用枚举 typeHandler

https://blog.csdn.net/bestcxx/article/details/85016413

https://segmentfault.com/a/1190000010755321

https://jeremyxu2010.github.io/2017/03/mybatis-generator%E4%BD%BF%E7%94%A8%E5%A4%87%E5%BF%98/