get number of files in a directory and its subdirectories
<p>using this code</p>

<pre><code>new File("/mnt/sdcard/folder").listFiles().length
</code></pre>

<p>returns a sum of folders and files in a particular directory without caring about <strong>subdirectories</strong>. 
I want to get number of all files in a directory and its subdirectories. </p>

<p>P.S. : hardly matters if it returns a sum of all the files and folders.</p>

<p>any help appreciated,
thanks</p>
