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.syntaxCheckers;
021
022
023import org.apache.directory.api.ldap.model.constants.SchemaConstants;
024import org.apache.directory.api.ldap.model.schema.SyntaxChecker;
025import org.apache.directory.api.util.Strings;
026import org.slf4j.Logger;
027import org.slf4j.LoggerFactory;
028
029
030/**
031 * A SyntaxChecker which verifies that a value is a Number according to RFC 4512.
032 * 
033 * From RFC 4512 :
034 * number  = DIGIT | ( LDIGIT 1*DIGIT )
035 * DIGIT   = %x30 | LDIGIT       ; "0"-"9"
036 * LDIGIT  = %x31-39             ; "1"-"9"
037 * 
038 *
039 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
040 */
041@SuppressWarnings("serial")
042public class NumberSyntaxChecker extends SyntaxChecker
043{
044    /** A logger for this class */
045    private static final Logger LOG = LoggerFactory.getLogger( NumberSyntaxChecker.class );
046
047
048    /**
049     * Creates a new instance of NumberSyntaxChecker.
050     */
051    public NumberSyntaxChecker()
052    {
053        super( SchemaConstants.NUMBER_SYNTAX );
054    }
055
056
057    /**
058     * {@inheritDoc}
059     */
060    public boolean isValidSyntax( Object value )
061    {
062        String strValue = null;
063
064        if ( value == null )
065        {
066            LOG.debug( "Syntax invalid for 'null'" );
067            return false;
068        }
069
070        if ( value instanceof String )
071        {
072            strValue = ( String ) value;
073        }
074        else if ( value instanceof byte[] )
075        {
076            strValue = Strings.utf8ToString( ( byte[] ) value );
077        }
078        else
079        {
080            strValue = value.toString();
081        }
082
083        // We should have at least one char
084        if ( strValue.length() == 0 )
085        {
086            LOG.debug( "Syntax invalid for '{}'", value );
087            return false;
088        }
089
090        // Check that each char is either a digit or a space
091        for ( int i = 0; i < strValue.length(); i++ )
092        {
093            switch ( strValue.charAt( i ) )
094            {
095                case '0':
096                case '1':
097                case '2':
098                case '3':
099                case '4':
100                case '5':
101                case '6':
102                case '7':
103                case '8':
104                case '9':
105                    continue;
106
107                default:
108                    LOG.debug( "Syntax invalid for '{}'", value );
109                    return false;
110            }
111        }
112
113        if ( ( strValue.charAt( 0 ) == '0' ) && strValue.length() > 1 )
114        {
115            // A number can't start with a '0' unless it's the only
116            // number
117            LOG.debug( "Syntax invalid for '{}'", value );
118            return false;
119        }
120
121        LOG.debug( "Syntax valid for '{}'", value );
122        return true;
123    }
124}