初学，不懂的内容

public class AdminAction extends ActionSupport implements ServletResponseAware{

private HttpServletResponse response;

ActionContext context =ActionContext.getContext();

Map session = context.getSession();  //获取HttpSession对象

Map request = (Map)context.get("request");   //获取request对象

/*变量存放从jsp中传过来的用户名和密码*/

private String userName;

private String passWord;