Spring Statemachine （Spring 状态机）是使用 Spring 框架下的状态机概念创建的一种应用程序开发框架。它使得状态机结构层次化，简化了配置状态机的过程。
详细功能：
Easy to use flat one level state machine for simple use cases.
Hierarchical state machine structure to ease complex state configuration.
State machine regions to provide even more complex state configurations.
Usage of triggers, transitions, guards and actions.
Type safe configuration adapter.
State machine event listeners.
Spring IOC integration to associate beans with a statemachine.
