For each state, there can be an action associated with state entry and exit.
对于每个状态，可以有一个与状态进入及退出相关联的操作。
2
There are also action buttons available to edit or delete the entry.
还提供了一些操作按钮来编辑或删除条目。
3
In addition, if you implement a validate method and set the validate flag in the corresponding action mapping entry in the Struts configuration file, the ActionServlet will invoke the validate method.