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 an Integer according to RFC 4517.
032     * 
033     * From RFC 4517 :
034     * 
035     * Integer = ( HYPHEN LDIGIT *DIGIT ) | number
036     * 
037     * From RFC 4512 :
038     * number  = DIGIT | ( LDIGIT 1*DIGIT )
039     * DIGIT   = %x30 | LDIGIT       ; "0"-"9"
040     * LDIGIT  = %x31-39             ; "1"-"9"
041     * HYPHEN  = %x2D                ; hyphen ("-")
042     * 
043     *
044     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
045     * @version $Rev$
046     */
047    public class IntegerSyntaxChecker extends SyntaxChecker
048    {
049        /** A logger for this class */
050        private static final Logger LOG = LoggerFactory.getLogger( IntegerSyntaxChecker.class );
051    
052        /** The serialVersionUID */
053        private static final long serialVersionUID = 1L;
054    
055        /**
056         * Creates a new instance of IntegerSyntaxChecker.
057         */
058        public IntegerSyntaxChecker()
059        {
060            super( SchemaConstants.INTEGER_SYNTAX );
061        }
062        
063        
064        /**
065         * {@inheritDoc}
066         */
067        public boolean isValidSyntax( Object value )
068        {
069            String strValue =null;
070    
071            if ( value == null )
072            {
073                LOG.debug( "Syntax invalid for '{}'", value );
074                return false;
075            }
076            
077            if ( value instanceof String )
078            {
079                strValue = ( String ) value;
080            }
081            else if ( value instanceof byte[] )
082            {
083                strValue = StringTools.utf8ToString( ( byte[] ) value ); 
084            }
085            else
086            {
087                strValue = value.toString();
088            }
089    
090            if ( strValue.length() == 0 )
091            {
092                LOG.debug( "Syntax invalid for '{}'", value );
093                return false;
094            }
095            
096            // The first char must be either a '-' or in [0..9].
097            // If it's a '0', then there should be any other char after
098            int pos = 0;
099            char c = strValue.charAt( pos );
100            
101            if ( c == '-' )
102            {
103                pos = 1;
104            }
105            else if ( !StringTools.isDigit( c ) )
106            {
107                LOG.debug( "Syntax invalid for '{}'", value );
108                return false;
109            }
110            else if ( c == '0' )
111            {
112                if ( strValue.length() > 1 )
113                {
114                    LOG.debug( "Syntax invalid for '{}'", value );
115                    return false;
116                }
117                else
118                {
119                    LOG.debug( "Syntax valid for '{}'", value );
120                    return true;
121                }
122            }
123                
124            // We must have at least a digit which is not '0'
125            if ( !StringTools.isDigit( strValue, pos ) )
126            {
127                LOG.debug( "Syntax invalid for '{}'", value );
128                return false;
129            }
130            else if ( StringTools.isCharASCII( strValue, pos, '0' ) )
131            {
132                LOG.debug( "Syntax invalid for '{}'", value );
133                return false;
134            }
135            else
136            {
137                pos++;
138            }
139            
140            while ( StringTools.isDigit( strValue, pos) )
141            {
142                pos++;
143            }
144            
145            boolean result = ( pos == strValue.length() );
146            
147            if ( result )
148            {
149                LOG.debug( "Syntax valid for '{}'", value );
150            }
151            else
152            {
153                LOG.debug( "Syntax invalid for '{}'", value );
154            }
155            
156            return result;
157        }
158    }