Servlet问题，急求解决！！！

public class ResultPageServlet extends HttpServlet {
  
  
   ResultPageService resultPageService = new ResultPageService();
  private  String name;
  
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
      doPost(request, response);
  }  public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("utf-8");
     name = request.getParameter("name");
    String method = request.getParameter("method");
    if("query".equals(method) ){
      this.query(request, response);
    }
  }
  protected void query(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {
    System.out.println("name="+name);
    List<Map<String , Object>> list_result = resultPageService.query(name);
    System.out.println("list_result="+list_result);
    request.setAttribute("list_result", list_result);
    request.getRequestDispatcher("result.jsp").forward(request, response);
    }
}在 request.getRequestDispatcher("result.jsp").forward(request, response);
报空指针异常  list_result 值也能打出来。