public static String decodeAsPrintableChars(final byte[] bytes,
                                                final Charset charset,
                                                final char unknownCharReplacement) {

        final CharsetDecoder charsetDecoder = getCharsetDecoder(charset);
        final StringBuilder stringBuilder = new StringBuilder();
        decodeAsPrintableChars(charsetDecoder, bytes, stringBuilder, unknownCharReplacement);
        return stringBuilder.toString();
    }
Replaces chr if it is a control character
stroom-util/src/main/java/stroom/util/string/HexDumpUtil.java