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.syntaxCheckers;
021    
022    
023    import org.apache.directory.shared.ldap.constants.SchemaConstants;
024    import org.apache.directory.shared.ldap.schema.SyntaxChecker;
025    import org.apache.directory.shared.ldap.util.StringTools;
026    import org.slf4j.Logger;
027    import 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     * @version $Rev$
041     */
042    public class NumberSyntaxChecker extends SyntaxChecker
043    {
044        /** A logger for this class */
045        private static final Logger LOG = LoggerFactory.getLogger( NumberSyntaxChecker.class );
046    
047        /** The serialVersionUID */
048        private static final long serialVersionUID = 1L;
049    
050        /**
051         * Creates a new instance of NumberSyntaxChecker.
052         */
053        public NumberSyntaxChecker()
054        {
055            super( SchemaConstants.NUMBER_SYNTAX );
056        }
057        
058    
059        /**
060         * {@inheritDoc}
061         */
062        public boolean isValidSyntax( Object value )
063        {
064            String strValue = null;
065    
066            if ( value == null )
067            {
068                LOG.debug( "Syntax invalid for '{}'", value );
069                return false;
070            }
071            
072            if ( value instanceof String )
073            {
074                strValue = ( String ) value;
075            }
076            else if ( value instanceof byte[] )
077            {
078                strValue = StringTools.utf8ToString( ( byte[] ) value ); 
079            }
080            else
081            {
082                strValue = value.toString();
083            }
084    
085            // We should have at least one char
086            if ( strValue.length() == 0 )
087            {
088                LOG.debug( "Syntax invalid for '{}'", value );
089                return false;
090            }
091            
092            // Check that each char is either a digit or a space
093            for ( int i = 0; i < strValue.length(); i++ )
094            {
095                switch ( strValue.charAt( i ) )
096                {
097                    case '0': 
098                    case '1' :
099                    case '2' :
100                    case '3' :
101                    case '4' :
102                    case '5' :
103                    case '6' :
104                    case '7' :
105                    case '8' :
106                    case '9' :
107                        continue;
108                        
109                    default : 
110                        LOG.debug( "Syntax invalid for '{}'", value );
111                        return false;
112                }
113            }
114            
115            if ( ( strValue.charAt( 0 ) == '0' ) && strValue.length() > 1 )
116            {
117                // A number can't start with a '0' unless it's the only
118                // number
119                LOG.debug( "Syntax invalid for '{}'", value );
120                return false;
121            }
122    
123            LOG.debug( "Syntax valid for '{}'", value );
124            return true;
125        }
126    }