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 * Copyright 2004 The Apache Software Foundation
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 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
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 *     http://www.apache.org/licenses/LICENSE-2.0
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package org.glassfish.grizzly.http.util;

import java.io.ByteArrayOutputStream;

Library of utility methods useful in dealing with converting byte arrays to and from strings of hexadecimal digits. Code from Ajp11, from Apache's JServ.
Author:Craig R. McClanahan
/** * Library of utility methods useful in dealing with converting byte arrays to and from strings of hexadecimal digits. * Code from Ajp11, from Apache's JServ. * * @author Craig R. McClanahan */
public final class HexUtils { // -------------------------------------------------------------- Constants
Table "isHexDigit".
/** * Table "isHexDigit". */
static final boolean[] IS_HEX_DIGIT = { false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, true, true, true, true, true, true, true, true, true, true, false, false, false, false, false, false, false, true, true, true, true, true, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, true, true, true, true, true, true, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, false, };
Table for HEX to DEC byte translation.
/** * Table for HEX to DEC byte translation. */
static final int[] DEC = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 00, 01, 02, 03, 04, 05, 06, 07, 8, 9, -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, };
Table for DEC to HEX byte translation.
/** * Table for DEC to HEX byte translation. */
static final byte[] HEX = { (byte) '0', (byte) '1', (byte) '2', (byte) '3', (byte) '4', (byte) '5', (byte) '6', (byte) '7', (byte) '8', (byte) '9', (byte) 'a', (byte) 'b', (byte) 'c', (byte) 'd', (byte) 'e', (byte) 'f' }; // --------------------------------------------------------- Static Methods
Convert a String of hexadecimal digits into the corresponding byte array by encoding each two hexadecimal digits as a byte.
Params:
  • digits – Hexadecimal digits representation
Throws:
  • IllegalArgumentException – if an invalid hexadecimal digit is found, or the input string contains an odd number of hexadecimal digits
/** * Convert a String of hexadecimal digits into the corresponding byte array by encoding each two hexadecimal digits as a * byte. * * @param digits Hexadecimal digits representation * * @exception IllegalArgumentException if an invalid hexadecimal digit is found, or the input string contains an odd * number of hexadecimal digits */
public static byte[] convert(String digits) { ByteArrayOutputStream baos = new ByteArrayOutputStream(); for (int i = 0; i < digits.length(); i += 2) { char c1 = digits.charAt(i); if (i + 1 >= digits.length()) { throw new IllegalArgumentException("hexUtil.odd"); } char c2 = digits.charAt(i + 1); byte b = 0; if (c1 >= '0' && c1 <= '9') { b += (c1 - '0') * 16; } else if (c1 >= 'a' && c1 <= 'f') { b += (c1 - 'a' + 10) * 16; } else if (c1 >= 'A' && c1 <= 'F') { b += (c1 - 'A' + 10) * 16; } else { throw new IllegalArgumentException("hexUtil.bad"); } if (c2 >= '0' && c2 <= '9') { b += c2 - '0'; } else if (c2 >= 'a' && c2 <= 'f') { b += c2 - 'a' + 10; } else if (c2 >= 'A' && c2 <= 'F') { b += c2 - 'A' + 10; } else { throw new IllegalArgumentException("hexUtil.bad"); } baos.write(b); } return baos.toByteArray(); }
Convert a byte array into a printable format containing a String of hexadecimal digit characters (two per byte).
Params:
  • bytes – Byte array representation
/** * Convert a byte array into a printable format containing a String of hexadecimal digit characters (two per byte). * * @param bytes Byte array representation */
public static String convert(byte bytes[]) { StringBuilder sb = new StringBuilder(bytes.length * 2); for (int i = 0; i < bytes.length; i++) { sb.append(convertDigit(bytes[i] >> 4)); sb.append(convertDigit(bytes[i] & 0x0f)); } return sb.toString(); }
Convert 4 hex digits to an int, and return the number of converted bytes.
Params:
  • hex – Byte array containing exactly four hexadecimal digits
Throws:
/** * Convert 4 hex digits to an int, and return the number of converted bytes. * * @param hex Byte array containing exactly four hexadecimal digits * * @exception IllegalArgumentException if an invalid hexadecimal digit is included */
public static int convert2Int(byte[] hex) { // Code from Ajp11, from Apache's JServ // assert b.length==4 // assert valid data int len; if (hex.length < 4) { return 0; } if (DEC[hex[0]] < 0) { throw new IllegalArgumentException("hexUtil.bad"); } len = DEC[hex[0]]; len = len << 4; if (DEC[hex[1]] < 0) { throw new IllegalArgumentException("hexUtil.bad"); } len += DEC[hex[1]]; len = len << 4; if (DEC[hex[2]] < 0) { throw new IllegalArgumentException("hexUtil.bad"); } len += DEC[hex[2]]; len = len << 4; if (DEC[hex[3]] < 0) { throw new IllegalArgumentException("hexUtil.bad"); } len += DEC[hex[3]]; return len; } public static int[] getDecBytes() { return DEC.clone(); }
[Private] Convert the specified value (0 .. 15) to the corresponding hexadecimal digit.
Params:
  • value – Value to be converted
/** * [Private] Convert the specified value (0 .. 15) to the corresponding hexadecimal digit. * * @param value Value to be converted */
private static char convertDigit(int value) { value &= 0x0f; if (value >= 10) { return (char) (value - 10 + 'a'); } else { return (char) (value + '0'); } } public static boolean isHexDigit(byte c) { return IS_HEX_DIGIT[c]; } public static boolean isHexDigit(int c) { return IS_HEX_DIGIT[c]; } public static int hexDigit2Dec(byte hexDigit) { return DEC[hexDigit]; } public static int hexDigit2Dec(int hexDigit) { return DEC[hexDigit]; } }