public String constructDN(final T o, final String parentDN) throws LDAPPersistException {
    final String existingDN = getEntryDN(o);
    if (existingDN != null) {
      return existingDN;
    }

    final LinkedHashMap<String, Attribute> attrMap = new LinkedHashMap<String, Attribute>(1);

    for (final FieldInfo i : rdnFields) {
      final Attribute a = i.encode(o, true);
      if (a == null) {
        throw new LDAPPersistException(
            ERR_OBJECT_HANDLER_RDN_FIELD_MISSING_VALUE.get(type.getName(), i.getField().getName()));
      }

      attrMap.put(toLowerCase(i.getAttributeName()), a);
    }

    for (final GetterInfo i : rdnGetters) {
      final Attribute a = i.encode(o);
      if (a == null) {
        throw new LDAPPersistException(
            ERR_OBJECT_HANDLER_RDN_GETTER_MISSING_VALUE.get(
                type.getName(), i.getMethod().getName()));
      }

      attrMap.put(toLowerCase(i.getAttributeName()), a);
    }

    return constructDN(o, parentDN, attrMap);
  }
  String constructDN(final T o, final String parentDN, final Map<String, Attribute> attrMap)
      throws LDAPPersistException {
    final String existingDN = getEntryDN(o);
    if (existingDN != null) {
      return existingDN;
    }

    final ArrayList<String> rdnNameList = new ArrayList<String>(1);
    final ArrayList<byte[]> rdnValueList = new ArrayList<byte[]>(1);
    for (final FieldInfo i : rdnFields) {
      final Attribute a = attrMap.get(toLowerCase(i.getAttributeName()));
      if (a == null) {
        throw new LDAPPersistException(
            ERR_OBJECT_HANDLER_RDN_FIELD_MISSING_VALUE.get(type.getName(), i.getField().getName()));
      }

      rdnNameList.add(a.getName());
      rdnValueList.add(a.getValueByteArray());
    }

    for (final GetterInfo i : rdnGetters) {
      final Attribute a = attrMap.get(toLowerCase(i.getAttributeName()));
      if (a == null) {
        throw new LDAPPersistException(
            ERR_OBJECT_HANDLER_RDN_GETTER_MISSING_VALUE.get(
                type.getName(), i.getMethod().getName()));
      }

      rdnNameList.add(a.getName());
      rdnValueList.add(a.getValueByteArray());
    }

    final String[] rdnNames = new String[rdnNameList.size()];
    rdnNameList.toArray(rdnNames);

    final byte[][] rdnValues = new byte[rdnNames.length][];
    rdnValueList.toArray(rdnValues);

    final RDN rdn = new RDN(rdnNames, rdnValues);

    if (parentDN == null) {
      return new DN(rdn, defaultParentDN).toString();
    } else {
      try {
        final DN parsedParentDN = new DN(parentDN);
        return new DN(rdn, parsedParentDN).toString();
      } catch (LDAPException le) {
        debugException(le);
        throw new LDAPPersistException(
            ERR_OBJECT_HANDLER_INVALID_PARENT_DN.get(type.getName(), parentDN, le.getMessage()),
            le);
      }
    }
  }
  private Filter createFilter(final T o, final AtomicBoolean addedRequiredOrAllowed)
      throws LDAPPersistException {
    final ArrayList<Attribute> attrs = new ArrayList<Attribute>(5);
    attrs.add(objectClassAttribute);

    for (final FieldInfo i : requiredFilterFields) {
      final Attribute a = i.encode(o, true);
      if (a == null) {
        throw new LDAPPersistException(
            ERR_OBJECT_HANDLER_FILTER_MISSING_REQUIRED_FIELD.get(i.getField().getName()));
      } else {
        attrs.add(a);
        addedRequiredOrAllowed.set(true);
      }
    }

    for (final GetterInfo i : requiredFilterGetters) {
      final Attribute a = i.encode(o);
      if (a == null) {
        throw new LDAPPersistException(
            ERR_OBJECT_HANDLER_FILTER_MISSING_REQUIRED_GETTER.get(i.getMethod().getName()));
      } else {
        attrs.add(a);
        addedRequiredOrAllowed.set(true);
      }
    }

    for (final FieldInfo i : alwaysAllowedFilterFields) {
      final Attribute a = i.encode(o, true);
      if (a != null) {
        attrs.add(a);
        addedRequiredOrAllowed.set(true);
      }
    }

    for (final GetterInfo i : alwaysAllowedFilterGetters) {
      final Attribute a = i.encode(o);
      if (a != null) {
        attrs.add(a);
        addedRequiredOrAllowed.set(true);
      }
    }

    for (final FieldInfo i : conditionallyAllowedFilterFields) {
      final Attribute a = i.encode(o, true);
      if (a != null) {
        attrs.add(a);
      }
    }

    for (final GetterInfo i : conditionallyAllowedFilterGetters) {
      final Attribute a = i.encode(o);
      if (a != null) {
        attrs.add(a);
      }
    }

    final ArrayList<Filter> comps = new ArrayList<Filter>(attrs.size());
    for (final Attribute a : attrs) {
      for (final ASN1OctetString v : a.getRawValues()) {
        comps.add(Filter.createEqualityFilter(a.getName(), v.getValue()));
      }
    }

    if (superclassHandler != null) {
      final Filter f = superclassHandler.createFilter(o, addedRequiredOrAllowed);
      if (f.getFilterType() == Filter.FILTER_TYPE_AND) {
        comps.addAll(Arrays.asList(f.getComponents()));
      } else {
        comps.add(f);
      }
    }

    return Filter.createANDFilter(comps);
  }