Cacher is the code snippet organizer for pro developers

final private char[] hexArray = "0123456789ABCDEF".toCharArray();

private String bytesToHex(byte[] bytes) {
    char[] hexChars = new char[bytes.length * 2];
    for (int j = 0; j < bytes.length; j++) {
        int v = bytes[j] & 0xFF;
        hexChars[j * 2] = hexArray[v >>> 4];
        hexChars[j * 2 + 1] = hexArray[v & 0x0F];
    }
    return new String(hexChars);
}

// To print byte array as ASCII:
String str = new String(buffer, StandardCharsets.US_ASCII);