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

java.nio.charset.CharsetDecoder does what you need. This class provides charset decoding with user-definable actions on different kinds of errors (see onMalformedInput() and onUnmappableCharacter()).

CharsetDecoder writes to an OutputStream, which you can pipe into an InputStream using java.io.PipedOutputStream, effectively creating a filtered InputStream.