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The private implementation classes of the Apache MyFaces Core JSF-2.3-next Implementation
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.myfaces.util.lang;
// minimal version of org.apache.commons.codec.binary.Hex to avoid commons-codec or JAXB DatatypeConverter dependency.
public class Hex
{
/**
* Used to build output as Hex
*/
private static final char[] DIGITS_LOWER
= {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
/**
* Used to build output as Hex
*/
private static final char[] DIGITS_UPPER
= {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
/**
* Converts a String representing hexadecimal values into an array of bytes of those same values. The
* returned array will be half the length of the passed String, as it takes two characters to represent any given
* byte. An exception is thrown if the passed String has an odd number of elements.
*
* @param data
* A String containing hexadecimal digits
*
* @return A byte array containing binary data decoded from the supplied char array.
*
* @throws IllegalArgumentException
* Thrown if an odd number or illegal of characters is supplied
* @since 1.11
*/
public static byte[] decodeHex(final String data) throws IllegalArgumentException
{
return decodeHex(data.toCharArray());
}
/**
* Converts an array of characters representing hexadecimal values into an array of bytes of those same values. The
* returned array will be half the length of the passed array, as it takes two characters to represent any given
* byte. An exception is thrown if the passed char array has an odd number of elements.
*
* @param data
* An array of characters containing hexadecimal digits
*
* @return A byte array containing binary data decoded from the supplied char array.
*
* @throws IllegalArgumentException
* Thrown if an odd number or illegal of characters is supplied
*/
public static byte[] decodeHex(final char[] data) throws IllegalArgumentException
{
final int len = data.length;
if ((len & 0x01) != 0)
{
throw new IllegalArgumentException("Odd number of characters.");
}
final byte[] out = new byte[len >> 1];
// two characters form the hex value.
for (int i = 0, j = 0; j < len; i++)
{
int f = toDigit(data[j], j) << 4;
j++;
f = f | toDigit(data[j], j);
j++;
out[i] = (byte) (f & 0xFF);
}
return out;
}
/**
* Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
* The returned array will be double the length of the passed array, as it takes two characters to represent any
* given byte.
*
* @param data
* a byte[] to convert to Hex characters
*
* @return A char[] containing lower-case hexadecimal characters
*/
public static char[] encodeHex(final byte[] data)
{
return encodeHex(data, true);
}
/**
* Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
* The returned array will be double the length of the passed array, as it takes two characters to represent any
* given byte.
*
* @param data
* a byte[] to convert to Hex characters
* @param toLowerCase
* true converts to lowercase, false to uppercase
*
* @return A char[] containing hexadecimal characters in the selected case
*
* @since 1.4
*/
public static char[] encodeHex(final byte[] data, final boolean toLowerCase)
{
return encodeHex(data, toLowerCase ? DIGITS_LOWER : DIGITS_UPPER);
}
/**
* Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order.
* The returned array will be double the length of the passed array, as it takes two characters to represent any
* given byte.
*
* @param data
* a byte[] to convert to Hex characters
* @param toDigits
* the output alphabet (must contain at least 16 chars)
*
* @return A char[] containing the appropriate characters from the alphabet
* For best results, this should be either upper- or lower-case hex.
*
* @since 1.4
*/
protected static char[] encodeHex(final byte[] data, final char[] toDigits)
{
final int l = data.length;
final char[] out = new char[l << 1];
// two characters form the hex value.
for (int i = 0, j = 0; i < l; i++)
{
out[j++] = toDigits[(0xF0 & data[i]) >>> 4];
out[j++] = toDigits[0x0F & data[i]];
}
return out;
}
/**
* Converts a hexadecimal character to an integer.
*
* @param ch
* A character to convert to an integer digit
* @param index
* The index of the character in the source
*
* @return An integer
*
* @throws IllegalArgumentException
* Thrown if ch is an illegal hex character
*/
protected static int toDigit(final char ch, final int index) throws IllegalArgumentException
{
final int digit = Character.digit(ch, 16);
if (digit == -1)
{
throw new IllegalArgumentException("Illegal hexadecimal character " + ch + " at index " + index);
}
return digit;
}
}