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.Chars;
026import org.apache.directory.shared.util.Strings;
027import org.slf4j.Logger;
028import org.slf4j.LoggerFactory;
029
030
031/**
032 * A SyntaxChecker which verifies that a value is a Boolean according to RFC 4517.
033 * 
034 * From RFC 4512 & RFC 4517 :
035 * 
036 * BitString    = SQUOTE *binary-digit SQUOTE "B"
037 * binary-digit = "0" / "1"
038 * SQUOTE  = %x27                           ; hyphen ("'")
039 * 
040 *
041 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
042 */
043@SuppressWarnings("serial")
044public class BitStringSyntaxChecker extends SyntaxChecker
045{
046    /** A logger for this class */
047    private static final Logger LOG = LoggerFactory.getLogger( BitStringSyntaxChecker.class );
048
049    /**
050     * 
051     * Creates a new instance of BitStringSyntaxChecker.
052     *
053     */
054    public BitStringSyntaxChecker()
055    {
056        super( SchemaConstants.BIT_STRING_SYNTAX );
057    }
058    
059
060    /**
061     * A shared and static method used to check that the string is a BitString.
062     * A BitString is a string of bits, between quotes and followed by a 'B' :
063     * 
064     * '01010110'B for instance
065     * 
066     * @param strValue The string to check
067     * @return <code>true</code> if the string is a BitString
068     */
069    public static boolean isValid( String strValue )
070    {
071        if ( strValue.length() == 0 )
072        {
073            LOG.debug( "Syntax invalid for '{}'", strValue );
074            return false;
075        }
076        
077        int pos = 0;
078        
079        // Check that the String respect the syntax : ' ([01]+) ' B
080        if ( ! Strings.isCharASCII( strValue, pos++, '\'' ) )
081        {
082            LOG.debug( "Syntax invalid for '{}'", strValue );
083            return false;
084        }
085
086        // We must have at least one bit
087        if ( ! Chars.isBit(strValue, pos++) )
088        {
089            LOG.debug( "Syntax invalid for '{}'", strValue );
090            return false;
091        }
092        
093        while ( Chars.isBit(strValue, pos) )
094        {
095            // Loop until we get a char which is not a 0 or a 1
096            pos++;
097        }
098
099        // Now, we must have a simple quote 
100        if ( ! Strings.isCharASCII( strValue, pos++, '\'' ) )
101        {
102            LOG.debug( "Syntax invalid for '{}'", strValue );
103            return false;
104        }
105
106        // followed by a 'B'
107        if ( ! Strings.isCharASCII( strValue, pos, 'B' ) )
108        {
109            LOG.debug( "Syntax invalid for '{}'", strValue );
110            return false;
111        }
112
113        LOG.debug( "Syntax valid for '{}'", strValue );
114        return true;
115    }
116
117    /**
118     * {@inheritDoc}
119     */
120    public boolean isValidSyntax( Object value )
121    {
122        String strValue = null;
123
124        if ( value == null )
125        {
126            LOG.debug( "Syntax invalid for 'null'" );
127            return false;
128        }
129        
130        if ( value instanceof String )
131        {
132            strValue = ( String ) value;
133        }
134        else if ( value instanceof byte[] )
135        {
136            strValue = Strings.utf8ToString((byte[]) value);
137        }
138        else
139        {
140            strValue = value.toString();
141        }
142
143        return isValid( strValue );
144    }
145}