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Java > Open Source Codes > org > apache > mina > common > support > ByteBufferHexDumper


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 (금, 13 7월 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 JavaDoc getHexdump(ByteBuffer in) {
54         int size = in.remaining();
55
56         if (size == 0) {
57             return "empty";
58         }
59
60         StringBuffer JavaDoc out = new StringBuffer JavaDoc((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 }
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