查找list中对象的某一属性最值

String lotNum = null;
for (InvLotLocTid invLotLocTid : invList) {
    if (lotNum == null) {
        lotNum = invLotLocTid.getLotNum();
    } else {
        if (lotNum.compareTo(invLotLocTid.getLotNum()) > 0) {
            lotNum = invLotLocTid.getLotNum();
        }
    }
}