Deu um branco

public class Class1 extends HttpServlet  {
  public void init(ServletConfig config){
    try{
      super.init(config);
    }
      catch(Exception e){
      e.printStackTrace();
    }
  }

  public String valor = "A";

  public HttpSession session;

  public void doIt(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    session = request.getSession();

    valor = request.getParameter("valor").trim();
  }
}


public class Class2 extends Class1 {
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    this.doIt(request, response);
    
    session.setAttribute(....);
    session.getAttribute(....);
    .....

    if ("A".equals(valor)) {
    .....
    }
  }
}