title: NullPointerException on unchanged bittorrent library of BitLet
body: <p>I just put a torrent on it, did not change the code.</p>
  
  <p>Console:</p>
  
  <pre><code>Exception in thread "main" java.lang.NullPointerException
      at org.bitlet.wetorrent.Metafile.&lt;init&gt;(Metafile.java:87)
      at org.bitlet.wetorrent.Sample.main(Sample.java:35)
  </code></pre>
  
  <p>It's on this:</p>
  
  <pre><code>35: Metafile metafile = new Metafile(new BufferedInputStream(new FileInputStream(filename)));
  </code></pre>
  
  <p>In Metafile code:</p>
  
  <pre><code>87: byte[] announceByteString = ((ByteBuffer) rootDictionary.get(ByteBuffer.wrap("announce".getBytes()))).array();
  </code></pre>
  
  <p>I just got the source code to begin studing it, but it doesn't run.</p>
  
  <hr>
  
  <p>Files:</p>
  
  <ul>
  <li><a href="https://github.com/bitletorg/bitlet/blob/master/src/main/java/org/bitlet/wetorrent/Sample.java" rel="nofollow">Sample.java</a></li>
  <li><a href="https://github.com/bitletorg/bitlet/blob/master/src/main/java/org/bitlet/wetorrent/Metafile.java" rel="nofollow">Metafile.java</a></li>
  <li><a href="https://github.com/bitletorg/bitlet/blob/master/src/main/java/org/bitlet/wetorrent/bencode/Bencode.java" rel="nofollow">Bencode.java</a> (a Metafile is a Bencode)</li>
  </ul>
  
  <p>I changed just one line (from Sample.java):</p>
  
  <p>From:</p>
  
  <pre><code>String filename = args[0];
  </code></pre>
  
  <p>To:</p>
  
  <pre><code>String filename = "C:\\Torrents\\Tao Of Jeet Kune Do By Bruce Lee (Pdf,Epub) Gooner.torrent";
  </code></pre>
  
  <p>It takes the torrent file name from the command line argument, I just put it on the code.</p>