HttpSession session = req.getSession();
        ServletContext servletContext = session.getServletContext();
        ApplicationContext ctx = WebApplicationContextUtils
                .getWebApplicationContext(servletContext);
        serviceUser = (ServiceUser) ctx.getBean("serviceUser");
        String action = (String) req.getParameter("actionName");
        if ("login".equals(action)) {
            session.removeAttribute("loginUser");
            session.removeAttribute("users");
            String username = (String) req.getParameter("username");
            String password = (String) req.getParameter("password");
            User user = serviceUser.login(username, password);
            if (user != null) {
                session.setAttribute("loginUser", user);
            } else {
                RequestDispatcher rd = getServletContext()
                        .getRequestDispatcher("/login.jsp");
                rd.forward((ServletRequest) req, (ServletResponse) resp);
                return;
            }
        } else if ("newUser".equals(action)) {
            String username = (String) req.getParameter("username");
            String password = (String) req.getParameter("password");
            User user = new User();
            user.setUsername(username);
            user.setPassword(password);
            try {
                serviceUser.addUser(user);
                session.setAttribute("newUser", true);
            } catch (Exception e) {
                e.printStackTrace();
                session.setAttribute("newUser", false);
            }
        } else if ("removeUsers".equals(action)) {
            String[] removeIds = req.getParameterValues("removeIds");
            session.removeAttribute("newUser");
            if (removeIds != null && removeIds.length > 0) {
                int[] ids = new int[removeIds.length];
                for (int i = 0; i < removeIds.length; i++) {
                    String is = removeIds[i];
                    int id = Integer.parseInt(is);
                    ids[i] = id;
                }
                try {
                    for (int id : ids) {
                        User user = serviceUser.getUser(id);
                        if ("admin".equals(user.getUsername())) {
                            continue;
                        }
                        serviceUser.deleteUser(user);
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        } else if ("changeUserMessage".equals(action)) {
            session.removeAttribute("newUser");
            try {
                Object object = session.getAttribute("loginUser");
                if (object instanceof User) {
                    User user = (User) object;
                    String password = (String) req.getParameter("password");
                    user.setPassword(password);
                    serviceUser.updateUser(user);
                    JSONObject json = new JSONObject();
                    JSONArray array = new JSONArray();
                    JSONObject member = null;
                    List<User> users = serviceUser.getUserAll();
                    for (User user2 : users) {
                        member = JSONObject.fromObject(user2);
                        array.add(member);
                    }
                    json.put("mydata", array);
                    PrintWriter pw = resp.getWriter();
                    pw.print(json.toString());
                    pw.close();
                    return;
                }

            } catch (Exception e) {
                e.printStackTrace();
            }
        }
        List<User> users = serviceUser.getUserAll();
        session.setAttribute("users", users);
        RequestDispatcher rd = getServletContext().getRequestDispatcher(
                "/info.jsp");
        rd.forward((ServletRequest) req, (ServletResponse) resp);