 <p>Uhm, theoretically, how would you know if it is unicode?</p> <p>This is the real question. Truthfully, you cannot know, but you can make a decent guess.</p> <p>See: <a href="http://stackoverflow.com/questions/499010/java-how-to-determine-the-correct-charset-encoding-of-a-stream">Java : How to determine the correct charset encoding of a stream</a> for more details. :)</p>