title: How can I read a file as unsigned bytes in Java?
body: <p>How can I read a file to bytes in Java?</p>
  
  <p>It is important to note that all the bytes need to be positive, i.e. the negative range cannot be used.</p>
  
  <p>Can this be done in Java, and if yes, how?</p>
  
  <p>I need to be able to multiply the contents of a file by a constant. I was assuming that I can read the bytes into a BigInteger and then multiply, however since some of the bytes are negative I am ending up with 12 13 15 -12 etc and get stuck.</p>