转自手册：AAOD Servlet执行函数的问题

General approach to access call session or message session variables
The general approach to gain access to call session or message session variables, either simple or complex, is to add code to a node.

For a Servlet node, override the following method:
public void servletImplementation(SCESession mySession)

For an other node, for example, Form, Menu, or Data, override the following method:
public void requestBegin(SCESession mySession)