如何获得json或xml格式的抽奖结果

I am making an app which manages lottery number that you purchased and compare to winning numbers. It will handle Powerball, Mega Millions and Superlotto Plus. But I do not know how to get the winning numbers, drawing dates, amount and other info from its web site using 'http get'. JSON or XML format or whatever format. Does anyone know how to get these data?I am making an app which manages lottery number