title: Convert UUID to hex string and vice versa
body: <p>A UUID in the form of "b2f0da40ec2c11e00000242d50cf1fbf" has been transformed (see the following code segment) into a hex string as 6232663064613430656332633131653030303030323432643530636631666266. I want to code a reverse routine and get it back to the original format as in "b2f0...", but had a hard time to do so, any help? </p>
  
  <pre><code>    byte[] bytes = uuid.getBytes("UTF-8");
  
      StringBuilder hex = new StringBuilder(bytes.length* 2);
      Formatter fmt = new Formatter(hex);
  
      for (byte b : bytes)
          fmt.format("%x", b);
  </code></pre>