如何获取异步加载的html页面的所有html源代码？

https://s.jipiao.trip.taobao.com/flight_search_result.htm?isAt=true#tripType=0&depCity=SH&depCityName=%E4%B8%8A%E6%B5%B7&arrCity=BJ&arrCityName=%E5%8C%97%E4%BA%AC&depDate=2012-09-29&arrDate=yyyy-mm-dd&searchBy=&n=1335456778261 https://s.jipiao.trip.taobao.com/flight_search_