/**
* Decodes data encoded using {@link #toHex(byte[],int,int) toHex}.
*
* @param hex data to be converted
* @param start offset
* @param len count
* @throws IOException if input does not represent hex encoded value
* @since 1.29
*/
public static byte[] fromHex(char[] hex, int start, int len) throws IOException {
if (hex == null) throw new IOException("null");
int i = hex.length;
if (i % 2 != 0) throw new IOException("odd length");
byte[] magic = new byte[i / 2];
for (; i > 0; i -= 2) {
String g = new String(hex, i - 2, 2);
try {
magic[(i / 2) - 1] = (byte) Integer.parseInt(g, 16);
} catch (NumberFormatException ex) {
throw new IOException(ex.getLocalizedMessage());
}
}
return magic;
}
