title: Fast way converting a byte array to corresponding Integer
body: <p>First, this sounds like the problem here:
  <a href="https://stackoverflow.com/questions/1026761/how-to-convert-a-byte-array-to-its-numeric-value-java">How to convert a byte array to its numeric value (Java)?</a></p>
  
  <p>But the origin of my Byte-Array is a String, something like this:</p>
  
  <pre><code>byte[] foo = new byte[8];
  foo = "12345678".getBytes();
  </code></pre>
  
  <p>Is there a faster way (yes its really about doing this quick) than<br>
  <code>Integer.parseInt(new String(foo))</code>?
  The String contains only digits which represent a Integer.</p>