Java 9 Hex Coder

Hex.java

import java.util.PrimitiveIterator;

import static java.lang.Character.digit;

public final class Hex {

  private Hex() {}

  private static final char[] HEX_CHARS = new char[]{'0', '1', '2', '3', '4', '5', '6', '7', '8',
      '9', 'a', 'b', 'c', 'd', 'e', 'f'};

  public static String encode(final byte[] data) {
    final char[] hex = new char[data.length << 1];
    int index = 0;
    for (final byte b : data) {
      hex[index++] = HEX_CHARS[(b >> 4) & 0xF];
      hex[index++] = HEX_CHARS[(b & 0xF)];
    }
    return new String(hex);
  }

  public static byte[] decode(final String hex) {
    final int len = hex.length() >> 1;
    final byte[] data = new byte[len];
    final PrimitiveIterator.OfInt codePoints = hex.codePoints().iterator();
    for (int i = 0;i < len;) {
      data[i++] = (byte) (digit(codePoints.nextInt(), 16) << 4 | digit(codePoints.nextInt(), 16));
    }
    return data;
  }
}