buyer = jndi.getBuyer();
            }        
            if (userMgmt == null) {
                userMgmt = jndi.getUserMgmt();
            }        
        }
        catch (Exception ex) {
            log.fatal("error initializing handler", ex);
            throw new ServletException("error initializing handler", ex);
        }
        finally {
        	if (jndi != null) { jndi.close(); }
        }
    }

    protected void doGet(HttpServletRequest request, 
                         HttpServletResponse response) 
        throws ServletException, IOException {
        log.debug("doGet() called");
        String command = request.getParameter(COMMAND_PARAM);
        log.debug("command=" + command);
        try {            
            if (command != null) {
                Handler handler = handlers.get(command);
                if (handler != null) {
                    log.debug("handler=" + handler);
                    handler.handle(request, response);
                }
                else {
                    request.setAttribute("handlers", handlers);
                    RequestDispatcher rd = 
                        getServletContext().getRequestDispatcher(
                            UNKNOWN_COMMAND_URL);
                            rd.forward(request, response);
                }
            }
            else {
                throw new Exception("no " + COMMAND_PARAM + " supplied"); 
            }
        }
        catch (Exception ex) {
            request.setAttribute(EXCEPTION_PARAM, ex);
            RequestDispatcher rd = getServletContext().getRequestDispatcher(
                    UNKNOWN_COMMAND_URL);
                    rd.forward(request, response);
        }
    }

    protected void doPost(HttpServletRequest request, 
                          HttpServletResponse response) 
        throws ServletException, IOException {
        log.debug("doPost() called, calling doGet()");
        doGet(request, response);
    }

    public void destroy() {
        log.debug("destroy() called");
    }
    
    private abstract class Handler {
        protected static final String RESULT_PARAM = "result";
        protected static final String MAINMENU_URL = 
            "/index.jsp";
        protected static final String DISPLAYUSER_URL = 
            "/WEB-INF/content/DisplayUser.jsp";
        protected static final String DISPLAYITEM_URL = 
            "/WEB-INF/content/DisplayItem.jsp";
        protected static final String DISPLAYITEMS_URL = 

                  getServletContext().getRequestDispatcher(BUYERMENU_URL);
                rd.forward(request, response);                
            }
            catch (Exception ex) {
                request.setAttribute(EXCEPTION_PARAM, ex);
                RequestDispatcher rd = getServletContext().getRequestDispatcher(
                    DISPLAY_EXCEPTION_URL);
                rd.forward(request, response);
            }
        }
    }

    private class CreateAccount extends Handler {
        public void handle(HttpServletRequest request, 
                HttpServletResponse response) 
                throws ServletException, IOException {
            try {
                String name = request.getParameter("name");
                String userId = request.getParameter("userId");
                
                Person user = new Person();
                user.setName(name);
                user.setUserId(userId);
                
                userMgmt.createUser(userId, name);
                user = userMgmt.getUserByUserId(userId);
                request.setAttribute(USER, user);
                
                RequestDispatcher rd = 
                  getServletContext().getRequestDispatcher(DISPLAYUSER_URL);
                rd.forward(request, response);                
            }
            catch (Exception ex) {
                request.setAttribute(EXCEPTION_PARAM, ex);
                RequestDispatcher rd = getServletContext().getRequestDispatcher(
                    DISPLAY_EXCEPTION_URL);
                rd.forward(request, response);
            }
        }
    }
    
    private class GetAvailableItems extends Handler {

                  getServletContext().getRequestDispatcher(ADMINMENU_URL);
                rd.forward(request, response);                
            }
            catch (Exception ex) {
                request.setAttribute(EXCEPTION_PARAM, ex);
                RequestDispatcher rd = getServletContext().getRequestDispatcher(
                    DISPLAY_EXCEPTION_URL);
                rd.forward(request, response);
            }
        }
    }

    private class Logout extends Handler {
        public void handle(HttpServletRequest request, 
                HttpServletResponse response) 
                throws ServletException, IOException {
            try {
                request.getSession().invalidate();
                
                RequestDispatcher rd = 
                  getServletContext().getRequestDispatcher(MAINMENU_URL);
                rd.forward(request, response);                
            }
            catch (Exception ex) {
                request.setAttribute(EXCEPTION_PARAM, ex);
                RequestDispatcher rd = getServletContext().getRequestDispatcher(
                    DISPLAY_EXCEPTION_URL);
                rd.forward(request, response);
            }
        }
    }
}