com.legstar.base.utils.HexUtils Maven / Gradle / Ivy
package com.legstar.base.utils;
/**
* Borrowed from Apache Commons codec
*/
public class HexUtils {
private HexUtils() {
}
/**
* 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'};
public static byte[] decodeHex(final String hexStr) {
final int len = hexStr.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(hexStr.charAt(j), j) << 4;
j++;
f = f | toDigit(hexStr.charAt(j), j);
j++;
out[i] = (byte) (f & 0xFF);
}
return out;
}
protected static int toDigit(final char ch, final int index) {
final int digit = Character.digit(ch, 16);
if (digit == -1) {
throw new IllegalArgumentException("Illegal hexadecimal character "
+ ch + " at index " + index);
}
return digit;
}
public static String encodeHex(final byte[] data) {
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++] = DIGITS_UPPER[(0xF0 & data[i]) >>> 4];
out[j++] = DIGITS_UPPER[0x0F & data[i]];
}
return String.valueOf(out);
}
}