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     */
020    package org.apache.directory.shared.ldap.schema.comparators;
021    
022    
023    import org.apache.directory.shared.asn1.primitives.OID;
024    import org.apache.directory.shared.ldap.schema.LdapComparator;
025    import org.apache.directory.shared.ldap.util.StringTools;
026    import org.slf4j.Logger;
027    import org.slf4j.LoggerFactory;
028    
029    
030    /**
031     * A comparator for Comparators. We compare the OIDs
032     * 
033     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
034     * @version $Rev$
035     */
036    public class ObjectIdentifierFirstComponentComparator extends LdapComparator<String>
037    {
038        /** A logger for this class */
039        private static final Logger LOG = LoggerFactory.getLogger( ObjectIdentifierFirstComponentComparator.class );
040    
041        /** The serialVersionUID */
042        private static final long serialVersionUID = 1L;
043    
044        /**
045         * The ObjectIdentifierFirstComponentComparator constructor. Its OID is the 
046         * ObjectIdentifierFirstComponentMatch matching rule OID.
047         */
048        public ObjectIdentifierFirstComponentComparator( String oid )
049        {
050            super( oid );
051        }
052    
053        
054        /**
055         * Get the OID from the SchemaObject description
056         */
057        private String getNumericOid( String s )
058        {
059            // Get the OID from the strings now
060            int pos = 0;
061            
062            if ( !StringTools.isCharASCII( s, pos++, '(' ) )
063            {
064                return null;
065            }
066            
067            while ( StringTools.isCharASCII( s, pos, ' ' ) )
068            {
069                pos++;
070            }
071            
072            int start = pos;
073            
074            while ( StringTools.isDigit( s, pos ) || StringTools.isCharASCII( s, pos, '.' ) )
075            {
076                pos++;
077            }
078            
079            String numericOid = s.substring( start, pos );
080            
081            if ( OID.isOID( numericOid ) )
082            {
083                return numericOid;
084            }
085            else
086            {
087                return null;
088            }
089        }
090        
091        /**
092         * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
093         */
094        public int compare( String s1, String s2 )
095        {
096            LOG.debug( "comparing ObjectIdentifierFirstComponent objects '{}' with '{}'", s1, s2 );
097    
098            // -------------------------------------------------------------------
099            // Handle some basis cases
100            // -------------------------------------------------------------------
101            if ( s1 == null )
102            {
103                return ( s2 == null ) ? 0 : -1;
104            }
105            
106            if ( s2 == null )
107            {
108                return -1;
109            }
110    
111            // Let's try to avoid a parse.
112            if ( s1.equals( s2 ) )
113            {
114                return 0;
115            }
116            
117            // Get the OID from the strings now
118            String oid1 = getNumericOid( s1 );
119            
120            if ( oid1 == null )
121            {
122                return -1;
123            }
124            
125            String oid2 = getNumericOid( s2 );
126    
127            if ( oid2 == null )
128            {
129                return -1;
130            }
131            
132            if ( oid1.equals( oid2 ) )
133            {
134                return 0;
135            }
136            else
137            {
138                return -1;
139            }
140        }
141    }