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.server.schema.bootstrap;
021    
022    
023    import java.io.Serializable;
024    import java.util.Comparator;
025    
026    import javax.naming.NamingException;
027    
028    import org.apache.directory.server.schema.registries.OidRegistry;
029    import org.apache.directory.server.schema.registries.Registries;
030    import org.apache.directory.shared.ldap.util.StringTools;
031    
032    
033    /**
034     * A comparator that sorts OIDs based on their numeric id value.  Needs a 
035     * OidRegistry to properly do it's job.  Public method to set the oid 
036     * registry will be used by the server after instantiation in deserialization.
037     *
038     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
039     * @version $Rev$
040     */
041    public class NameOrNumericIdComparator implements Comparator, Serializable
042    {
043        private static final long serialVersionUID = 1L;
044        private transient OidRegistry registry;
045    
046        
047        public NameOrNumericIdComparator( OidRegistry registry )
048        {
049            this.registry = registry;
050        }
051        
052        
053        public NameOrNumericIdComparator()
054        {
055        }
056        
057        
058        /* (non-Javadoc)
059         * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
060         */
061        public int compare( Object o1, Object o2 )
062        {
063            String s1 = getNumericIdString( o1 );
064            String s2 = getNumericIdString( o2 );
065    
066            if ( s1 == null && s2 == null )
067            {
068                return 0;
069            }
070            
071            if ( s1 == null )
072            {
073                return -1;
074            }
075            
076            if ( s2 == null )
077            {
078                return 1;
079            }
080            
081            return s1.compareTo( s2 );
082        }
083        
084        
085        public void setRegistries( Registries registries )
086        {
087            registry = registries.getOidRegistry();
088        }
089        
090        
091        String getNumericIdString( Object obj )
092        {
093            String strValue;
094    
095            if ( obj == null )
096            {
097                return null;
098            }
099            
100            if ( obj instanceof String )
101            {
102                strValue = ( String ) obj;
103            }
104            else if ( obj instanceof byte[] )
105            {
106                strValue = StringTools.utf8ToString( ( byte[] ) obj ); 
107            }
108            else
109            {
110                strValue = obj.toString();
111            }
112            
113            if ( strValue.length() == 0 )
114            {
115                return "";
116            }
117    
118            if ( registry.hasOid( strValue ) )
119            {
120                try
121                {
122                    return registry.getOid( strValue );
123                }
124                catch ( NamingException e )
125                {
126                    throw new RuntimeException( "Failed to lookup OID for " + strValue, e );
127                }
128            }
129            
130            return strValue;
131        }
132    }