title: encoding jpeg in java without disk writing
body: <p>as the title say i need to find some java jpeg encoder (it's good both source code or external library) that given an array that represent a raw pixel image or a BufferedImage can encode it <strong>without writing</strong> anything on file and return the encoded image possibly trough an array of some kind, with at least possibility to choose image quality and possibly with good efficiency.</p>
  
  <p>NB: the array/image type input required (byte, int, argb, rgb, bgr, yuv...) doesn't matter for me, i can make approppriate conversions</p>