How can I know a DataInput size?
<pre><code>public void readFields(DataInput in) throws IOException{
    //How can I set up the byteArray size here?
    //DataInput does not have available() or length() method.
    byte[] videoByteArray = new byte[size];
    in.readFully(videoByteArray);
}
</code></pre>

<p>How can I know the DataInput size? Before I read all data into a byte array, I need set up the size first.</p>
