| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| * |
| */ |
| package org.apache.directory.shared.ldap.schema.comparators; |
| |
| |
| import org.apache.directory.shared.ldap.entry.StringValue; |
| import org.apache.directory.shared.ldap.schema.LdapComparator; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| |
| /** |
| * A comparator for CSN. |
| * |
| * The CSN are ordered depending on an evaluation of its component, in this order : |
| * - time, |
| * - changeCount, |
| * - sid |
| * - modifierNumber |
| * |
| * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> |
| */ |
| public class CsnComparator extends LdapComparator<Object> |
| { |
| /** A logger for this class */ |
| private static final Logger LOG = LoggerFactory.getLogger( CsnComparator.class ); |
| |
| /** The serialVersionUID */ |
| private static final long serialVersionUID = 1L; |
| |
| /** |
| * The CsnComparator constructor. Its OID is the CsnMatch matching |
| * rule OID. |
| */ |
| public CsnComparator( String oid ) |
| { |
| super( oid ); |
| } |
| |
| |
| /** |
| * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object) |
| */ |
| public int compare( Object csnObj1, Object csnObj2 ) |
| { |
| LOG.debug( "comparing CSN objects '{}' with '{}'", csnObj1, csnObj2 ); |
| |
| if ( csnObj1 == csnObj2 ) |
| { |
| return 0; |
| } |
| |
| // ------------------------------------------------------------------- |
| // Handle some basis cases |
| // ------------------------------------------------------------------- |
| if ( csnObj1 == null ) |
| { |
| return ( csnObj2 == null ) ? 0 : -1; |
| } |
| |
| if ( csnObj2 == null ) |
| { |
| return 1; |
| } |
| |
| String csnStr1 = null; |
| String csnStr2 = null; |
| |
| if ( csnObj1 instanceof StringValue ) |
| { |
| csnStr1 = ( ( StringValue ) csnObj1 ).get(); |
| } |
| else |
| { |
| csnStr1 = csnObj1.toString(); |
| } |
| |
| if ( csnObj2 instanceof StringValue ) |
| { |
| csnStr2 = ( ( StringValue ) csnObj2 ).get(); |
| } |
| else |
| { |
| csnStr2 = csnObj2.toString(); |
| } |
| |
| return csnStr1.compareTo( csnStr2 ); |
| } |
| } |