Listのインデックス表示
よく聞かれます。。
Displaying the row number or index in a spark List
http://flexponential.com/2010/02/08/displaying-the-row-number-or-index-in-a-spark-list/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+flexponential+%28Flexponential%29