apollo-portal/src/main/java/com/ctrip/framework/apollo/portal/spi/ldap/FilterLdapByGroupUserSearch.java/FilterLdapByGroupUserSearch/searchUserById
class FilterLdapByGroupUserSearch:  private Name searchUserById(String userId) {
    SpringSecurityLdapTemplate template = new SpringSecurityLdapTemplate(this.contextSource);
    template.setSearchControls(searchControls);
    return template.searchForObject(query().where(this.loginIdAttrName).is(userId),
        ctx -> ((DirContextAdapter) ctx).getDn());
  }