title: how to write java udf in impala
body: <p>I want to implement <code>running total</code> example in <code>Impala</code> like below :</p>
  
  <pre><code>DATE        |   DAY |   COUNT   |   Total
  2014-11-12  |   1   |   12      |   12
  2014-11-13  |   2   |   32      |   44
  2014-11-14  |   3   |   50      |   94
  
  To solve this problem using Impala, we might need temp variable like in MySql, which Impala does not support.
  </code></pre>
  
  <p>For this, I want to use java udf to add first row total with second row count. So that I will get second row total. How could I do this. Please suggest. 
  Please also provide steps to <code>add jar</code> into <code>Impala</code>.
  Your help will be very helpful.</p>