如何通过ldap中的特定对象类获取所有属性定义？

Question

My aim is to retrieve all attributes defined on LDAP server by a given objectclass. What I have done so far is:

List<SearchResult> searchLdapUsers = searchLdapUsers(ldapConfig, null, null, null, null, null, 0);
if (searchLdapUsers != null  && searchLdapUsers.size() > 0) {
    for (SearchResult searchResult : searchLdapUsers) {
        Attributes attrs = searchResult.getAttributes();
        if (attrs != null) {
            NamingEnumeration<? extends Attribute> all = attrs.getAll();
            while (all.hasMoreElements()) {
                Attribute attribute = (Attribute) all.nextElement();
                hs.put(attribute.getID(), attribute.getID());
            }
        }
    }
}

This code will query all users from LDAP server and get attribute definition. This is working fine but will get problem with large number of users.

Is there any other way to find directly the given object class and get all attribute definition inside?

Answer 1

Most LDAP servers expose their schema through LDAP, and per LDAP specifications, every entry should have an operational attribute (subSchemaSubEntry) that points to the Schema entry. So reading the schema, should give you all objectClasses and their attributes definitions.