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.shared.ldap.model.schema.syntaxCheckers;
021
022
023import org.apache.directory.shared.ldap.model.constants.SchemaConstants;
024import org.apache.directory.shared.ldap.model.schema.SyntaxChecker;
025import org.apache.directory.shared.util.Strings;
026import org.slf4j.Logger;
027import org.slf4j.LoggerFactory;
028
029
030/**
031 * A SyntaxChecker which verifies that a value is a valid DerefAlias. We
032 * have four possible values :
033 * <ul>
034 * <li>NEVER</li>
035 * <li>SEARCHING</li>
036 * <li>FINDING</li>
037 * <li>ALWAYS</li>
038 * </ul>
039 * The value is case insensitive
040 *
041 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
042 */
043@SuppressWarnings("serial")
044public class DerefAliasSyntaxChecker extends SyntaxChecker
045{
046    /** A logger for this class */
047    private static final Logger LOG = LoggerFactory.getLogger( DerefAliasSyntaxChecker.class );
048
049    /**
050     * Creates a new instance of DerefAliasSyntaxChecker.
051     */
052    public DerefAliasSyntaxChecker()
053    {
054        super( SchemaConstants.DEREF_ALIAS_SYNTAX );
055    }
056    
057    
058    /**
059     * {@inheritDoc}
060     */
061    public boolean isValidSyntax( Object value )
062    {
063        String strValue = null;
064
065        if ( value == null )
066        {
067            LOG.debug( "Syntax invalid for 'null'" );
068            return false;
069        }
070        
071        if ( value instanceof String )
072        {
073            strValue = ( String ) value;
074        }
075        else if ( value instanceof byte[] )
076        {
077            strValue = Strings.utf8ToString((byte[]) value);
078        }
079        else
080        {
081            strValue = value.toString();
082        }
083
084        strValue = Strings.trim( Strings.toLowerCase( strValue ) );
085        
086        return ( "never".equals( strValue ) || 
087                 "finding".equals(  strValue ) || 
088                 "searching".equals( strValue ) ||
089                 "always".equals( strValue ));
090    }
091}