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.codec.stateful.examples;
021
022
023 import java.nio.ByteBuffer;
024
025 import org.apache.directory.shared.asn1.codec.EncoderException;
026 import org.apache.directory.shared.asn1.codec.stateful.EncoderCallback;
027 import org.apache.directory.shared.asn1.codec.stateful.EncoderMonitor;
028 import org.apache.directory.shared.asn1.codec.stateful.EncoderMonitorAdapter;
029 import org.apache.directory.shared.asn1.codec.stateful.StatefulEncoder;
030
031
032 /**
033 * Document me.
034 *
035 * @author <a href="mailto:dev@directory.apache.org"> Apache Directory Project</a>
036 * @version $Rev: 664290 $
037 */
038 public class HexEncoder implements StatefulEncoder
039 {
040 private static final int CHUNK_SZ = 128;
041
042 private ByteBuffer buf = ByteBuffer.allocate( CHUNK_SZ );
043
044 private EncoderMonitor monitor = new EncoderMonitorAdapter();
045
046 private EncoderCallback cb = new EncoderCallback()
047 {
048 public void encodeOccurred( StatefulEncoder encoder, Object encoded )
049 {
050 }
051 };
052
053 private final byte[] HEXCHAR_LUT =
054 { ( byte ) '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
055
056
057 /**
058 * Transforms a decoded ByteArray of binary data into a stream of ASCII hex
059 * characters.
060 *
061 * @param obj
062 * @throws org.apache.directory.shared.asn1.codec.EncoderException
063 */
064 public void encode( Object obj ) throws EncoderException
065 {
066 ByteBuffer raw = ( ByteBuffer ) obj;
067
068 if ( raw == null || !raw.hasRemaining() )
069 {
070 return;
071 }
072
073 /*
074 * Keep encoding one byte at a time if we have remaining bytes in the
075 * raw buffer and there's space for 2 hex character bytes in the
076 * resultant hex encoded buffer.
077 */
078 while ( raw.hasRemaining() )
079 {
080 if ( !buf.hasRemaining() )
081 {
082 buf.flip();
083 cb.encodeOccurred( this, buf );
084 monitor.callbackOccured( this, cb, buf );
085 buf.clear();
086 }
087
088 byte bite = raw.get();
089 buf.put( HEXCHAR_LUT[( bite >> 4 ) & 0x0000000F] );
090 buf.put( HEXCHAR_LUT[bite & 0x0000000F] );
091 }
092
093 buf.flip();
094 cb.encodeOccurred( this, buf );
095 monitor.callbackOccured( this, cb, buf );
096 buf.clear();
097 }
098
099
100 public void setCallback( EncoderCallback cb )
101 {
102 EncoderCallback old = this.cb;
103 this.cb = cb;
104 monitor.callbackSet( this, old, cb );
105 }
106
107
108 public void setEncoderMonitor( EncoderMonitor monitor )
109 {
110 this.monitor = monitor;
111 }
112 }