001/*
002 *  Licensed to the Apache Software Foundation (ASF) under one
003 *  or more contributor license agreements.  See the NOTICE file
004 *  distributed with this work for additional information
005 *  regarding copyright ownership.  The ASF licenses this file
006 *  to you under the Apache License, Version 2.0 (the
007 *  "License"); you may not use this file except in compliance
008 *  with the License.  You may obtain a copy of the License at
009 *  
010 *    http://www.apache.org/licenses/LICENSE-2.0
011 *  
012 *  Unless required by applicable law or agreed to in writing,
013 *  software distributed under the License is distributed on an
014 *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 *  KIND, either express or implied.  See the License for the
016 *  specific language governing permissions and limitations
017 *  under the License. 
018 *  
019 */
020package org.apache.directory.api.ldap.model.schema.comparators;
021
022
023import org.apache.directory.api.ldap.model.exception.LdapException;
024import org.apache.directory.api.ldap.model.schema.LdapComparator;
025import org.apache.directory.api.ldap.model.schema.Normalizer;
026import org.slf4j.Logger;
027import org.slf4j.LoggerFactory;
028
029
030/**
031 * A comparator which normalizes a value first before using a subordinate
032 * comparator to compare them.
033 * 
034 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
035 */
036public class NormalizingComparator extends LdapComparator<String>
037{
038    /** The serial version UID */
039    private static final long serialVersionUID = 2L;
040
041    /** A logger for this class */
042    private static final Logger LOG = LoggerFactory.getLogger( NormalizingComparator.class );
043
044    /** the Normalizer to normalize values with before comparing */
045    private Normalizer normalizer;
046
047    /** the underlying comparator to use for comparisons */
048    private LdapComparator<String> comparator;
049
050    private boolean onServer = false;
051
052
053    /**
054     * A comparator which normalizes a value first before comparing them.
055     * 
056     * @param oid The Comparator's OID
057     * @param normalizer the Normalizer to normalize values with before comparing
058     * @param comparator the underlying comparator to use for comparisons
059     */
060    public NormalizingComparator( String oid, Normalizer normalizer, LdapComparator<String> comparator )
061    {
062        super( oid );
063        this.normalizer = normalizer;
064        this.comparator = comparator;
065    }
066
067
068    /**
069     * {@inheritDoc}
070     */
071    public int compare( String o1, String o2 )
072    {
073        if ( onServer )
074        {
075            return comparator.compare( o1, o2 );
076        }
077
078        String n1;
079        String n2;
080
081        try
082        {
083            n1 = normalizer.normalize( o1 );
084        }
085        catch ( LdapException e )
086        {
087            LOG.warn( "Failed to normalize: " + o1, e );
088            n1 = o1;
089        }
090
091        try
092        {
093            n2 = normalizer.normalize( o2 );
094        }
095        catch ( LdapException e )
096        {
097            LOG.warn( "Failed to normalize: " + o2, e );
098            n2 = o2;
099        }
100
101        return comparator.compare( n1, n2 );
102    }
103
104
105    /**
106     * {@inheritDoc}
107     * 
108     * This implementation makes sure we update the oid property of the contained normalizer and 
109     * comparator.
110     */
111    @Override
112    public void setOid( String oid )
113    {
114        super.setOid( oid );
115        normalizer.setOid( oid );
116        comparator.setOid( oid );
117    }
118
119
120    /**
121     * tells that the normalizingComparator should not normalize values which are
122     * already normalized on the server 
123     */
124    public void setOnServer()
125    {
126        this.onServer = true;
127    }
128}