activiti

https://juejin.im/post/5aafa3eef265da23784015b9

https://www.activiti.org/userguide/

https://blog.csdn.net/a286440556/article/details/86479783

https://www.cnblogs.com/jpfss/p/11076242.html

https://segmentfault.com/a/1190000021279081