1 // Copyright (c) 1999-2004 Brian Wellington (bwelling (at) 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 } 57
