1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 *
19 */
20 package org.apache.mina.common.support;
21
22 import org.apache.mina.common.ByteBuffer;
23
24 /**
25 * Provides utility methods for ByteBuffers.
26 *
27 * @author The Apache Directory Project (mina-dev@directory.apache.org)
28 * @version $Rev: 555855 $, $Date: 2007-07-13 12:19:00 +0900 (Fri, 13 Jul 2007) $
29 */
30 public class ByteBufferHexDumper {
31 private static final byte[] highDigits;
32
33 private static final byte[] lowDigits;
34
35 // initialize lookup tables
36 static {
37 final byte[] digits = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
38 '9', 'A', 'B', 'C', 'D', 'E', 'F' };
39
40 int i;
41 byte[] high = new byte[256];
42 byte[] low = new byte[256];
43
44 for (i = 0; i < 256; i++) {
45 high[i] = digits[i >>> 4];
46 low[i] = digits[i & 0x0F];
47 }
48
49 highDigits = high;
50 lowDigits = low;
51 }
52
53 public static String getHexdump(ByteBuffer in) {
54 int size = in.remaining();
55
56 if (size == 0) {
57 return "empty";
58 }
59
60 StringBuffer out = new StringBuffer((in.remaining() * 3) - 1);
61
62 int mark = in.position();
63
64 // fill the first
65 int byteValue = in.get() & 0xFF;
66 out.append((char) highDigits[byteValue]);
67 out.append((char) lowDigits[byteValue]);
68 size--;
69
70 // and the others, too
71 for (; size > 0; size--) {
72 out.append(' ');
73 byteValue = in.get() & 0xFF;
74 out.append((char) highDigits[byteValue]);
75 out.append((char) lowDigits[byteValue]);
76 }
77
78 in.position(mark);
79
80 return out.toString();
81 }
82 }