public function changeUserRoles($id, array $roles)
{
$user = $this->getUser($id);
if (empty($user)) {
throw $this->createServiceException('用户不存在，设置用户角色失败。');
}
if (empty($roles)) {
throw $this->createServiceException('用户角色不能为空');
}
if (!in_array('ROLE_USER', $roles)) {
throw $this->createServiceException('用户角色必须包含ROLE_USER');
}
$allowedRoles = array('ROLE_USER', 'ROLE_ADMIN', 'ROLE_SUPER_ADMIN', 'ROLE_TEACHER');
$notAllowedRoles = array_diff($roles, $allowedRoles);
if (!empty($notAllowedRoles)) {
throw $this->createServiceException('用户角色不正确，设置用户角色失败。');
}
$this->getUserDao()->updateUser($id, UserSerialize::serialize(array('roles' => $roles)));
$this->getLogService()->info('user', 'change_role', "设置用户{$user['nickname']}(#{$user['id']})的角色为：" . implode(',', $roles));
}
