/**
  * 管理员登录 
  */
 public function loginAction()
 {
     $request = $this->getRequest();
     $admin_service = new AdminService();
     //用户已登录跳转到后台首页
     if ($admin_service->checkLogin() == true) {
         return $this->redirect('/admin');
     }
     if ($request->isPost()) {
         $username = trim($request->getParam('username'));
         $password = $request->getParam('password');
         $captcha = $request->getParam('captcha');
         $remember = $request->getParam('remember');
         if (empty($username)) {
             return $this->showJson(1, '请输入用户名');
         }
         if (empty($password) || strlen($password) < 6) {
             return $this->showJson(2, '请输入6位以上密码');
         }
         if ($admin_service->checkCaptcha($captcha) == false) {
             return $this->showJson(3, '帐号或密码有误,请重新输入');
         }
         $admin = $admin_service->getAdminByUsername($username);
         if (empty($admin)) {
             return $this->showJson(403, '帐号或密码有误,请重新输入');
         }
         //当天密码错误超过500次
         if ($admin['error_times'] > 500) {
             return $this->showJson(4, '帐号密码输入错误次数过多,请明日再试。');
         }
         //验证密码是否正确
         if ($admin['password'] == Password::Encryption($username, $password)) {
             $admin_service->adminLogin($username, '', $remember);
         } else {
             $admin_data = array();
             if (Star_Date::getDate() == $admin['error_date']) {
                 $admin_data = array('error_date' => Star_Date::getDate(), 'error_times' => 'error_times + 1');
             } else {
                 $admin_data = array('error_date' => Star_Date::getDate(), 'error_times' => 1);
             }
             $admin_service->updateAdmin($admin['admin_id'], $admin_data, false);
             return $this->showJson(403, '帐号或密码有误,请重新输入');
         }
         return $this->showJson(0, '登录成功');
     }
 }