如下代码在注释行会报错，原因是：getSeatTravelerInfo()时值为空，对空对象addAll会报错
SeatBookingInfo b=new SeatBookingInfo();
b.setIndex(index);
b.setContactInfo(contactInfo);
// b.getSeatTravelerInfo().addAll(seatTravelerInfo);
b.setSeatTravelerInfo(seatTravelerInfo);
原文：http://www.cnblogs.com/shoubianxingchen/p/4267957.html