title: convert ByteArrayOutputStream to FileInputStream
body: <p>I have stream saved in <code>ByteArrayOutputStream</code>. now I want to to read that in <code>FileInputStream</code>. how Can I do that?</p>
  
  <p>it's my outputStream.</p>
  
  <pre><code>...
  OutputStream out = new ByteArrayOutputStream();
  ...
  </code></pre>
  
  <p>now how to read that, from <code>FileInputStream</code>?</p>