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.asn1.util;
021    
022    
023    import org.apache.directory.shared.asn1.ber.tlv.Value;
024    import org.apache.directory.shared.i18n.I18n;
025    import org.slf4j.Logger;
026    import org.slf4j.LoggerFactory;
027    
028    
029    /**
030     * Parse and decode a Boolean value.
031     * 
032     * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
033     * @version $Rev: 912399 $, $Date: 2010-02-21 21:52:31 +0100 (Sun, 21 Feb 2010) $
034     */
035    public class BooleanDecoder
036    {
037        /** The logger */
038        private static final Logger log = LoggerFactory.getLogger( BooleanDecoder.class );
039    
040    
041        // ~ Methods
042        // ------------------------------------------------------------------------------------
043    
044        /**
045         * Parse a byte buffer and send back a booelan.
046         * 
047         * @param value
048         *            The byte buffer to parse
049         * @return A boolean.
050         * @throws BooleanDecoderException
051         *             Thrown if the byte stream does not contains a boolean
052         */
053        public static boolean parse( Value value ) throws BooleanDecoderException
054        {
055            byte[] bytes = value.getData();
056    
057            if ( ( bytes == null ) || ( bytes.length == 0 ) )
058            {
059                throw new BooleanDecoderException( I18n.err( I18n.ERR_00034 ) );
060            }
061    
062            if ( bytes.length != 1 )
063            {
064                throw new BooleanDecoderException( I18n.err( I18n.ERR_00035 ) );
065            }
066    
067            if ( ( bytes[0] != 0 ) && ( bytes[0] != ( byte ) 0xFF ) )
068            {
069                log.warn( "A boolean must be encoded with a 0x00 or a 0xFF value" );
070            }
071    
072            return bytes[0] != 0;
073        }
074    }