1、使用开源的Activiti做流程https://github.com/Activiti/Activiti
2、相关博客：https://www.baeldung.com/java-activiti
3、userguid: https://www.activiti.org/userguide/index.html?_ga=2.55182893.76071610.1499064413-1368418377.1499064413#eclipseDesignerInstallation
4、文档：https://www.activiti.org/documentation