apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/spi/springsecurity/SpringSecurityUserService.java/SpringSecurityUserService/findByUserId
class SpringSecurityUserService:  @Override
  public UserInfo findByUserId(String userId) {
    UserPO userPO = userRepository.findByUsername(userId);
    return userPO == null ? null : userPO.toUserInfo();
  }