How to detect illegal UTF-8 byte sequences to replace them in java inputstream?

Question

The file in question is not under my control. Most byte sequences are valid UTF-8, it is not ISO-8859-1 (or an other encoding). I want to do my best do extract as much informat

Answer 1

The behaviour you want is already the default for InputStreamReader. So there is no need to specify it yourself. This suffices:

final BufferedInputStream in = new BufferedInputStream(istream);
final Reader inputReader = new InputStreamReader(in, StandardCharsets.UTF_8);