This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
sandy indiranagar wrote:is it because of the excel api or there is some other format in which these columns with mobile numbers should be saved..
No, it's nothing to do with the API or the data format. It's all to do with the way that your code displays those numbers. You could use a DecimalFormat object to specify how to display it, or a Formatter, or the System.out.format() method. It's up to you.