Shuyi Chen | d7955ce | 2013-05-22 14:51:55 -0700 | [diff] [blame] | 1 | // Copyright (c) 1999-2004 Brian Wellington (bwelling@xbill.org) |
| 2 | |
| 3 | package org.xbill.DNS.utils; |
| 4 | |
| 5 | /** |
| 6 | * A routine to produce a nice looking hex dump |
| 7 | * |
| 8 | * @author Brian Wellington |
| 9 | */ |
| 10 | |
| 11 | public class hexdump { |
| 12 | |
| 13 | private static final char [] hex = "0123456789ABCDEF".toCharArray(); |
| 14 | |
| 15 | /** |
| 16 | * Dumps a byte array into hex format. |
| 17 | * @param description If not null, a description of the data. |
| 18 | * @param b The data to be printed. |
| 19 | * @param offset The start of the data in the array. |
| 20 | * @param length The length of the data in the array. |
| 21 | */ |
| 22 | public static String |
| 23 | dump(String description, byte [] b, int offset, int length) { |
| 24 | StringBuffer sb = new StringBuffer(); |
| 25 | |
| 26 | sb.append(length + "b"); |
| 27 | if (description != null) |
| 28 | sb.append(" (" + description + ")"); |
| 29 | sb.append(':'); |
| 30 | |
| 31 | int prefixlen = sb.toString().length(); |
| 32 | prefixlen = (prefixlen + 8) & ~ 7; |
| 33 | sb.append('\t'); |
| 34 | |
| 35 | int perline = (80 - prefixlen) / 3; |
| 36 | for (int i = 0; i < length; i++) { |
| 37 | if (i != 0 && i % perline == 0) { |
| 38 | sb.append('\n'); |
| 39 | for (int j = 0; j < prefixlen / 8 ; j++) |
| 40 | sb.append('\t'); |
| 41 | } |
| 42 | int value = (int)(b[i + offset]) & 0xFF; |
| 43 | sb.append(hex[(value >> 4)]); |
| 44 | sb.append(hex[(value & 0xF)]); |
| 45 | sb.append(' '); |
| 46 | } |
| 47 | sb.append('\n'); |
| 48 | return sb.toString(); |
| 49 | } |
| 50 | |
| 51 | public static String |
| 52 | dump(String s, byte [] b) { |
| 53 | return dump(s, b, 0, b.length); |
| 54 | } |
| 55 | |
| 56 | } |