用Collections.sort方法对现有的List重新进行排序

//重新将relList里的数据按照sequenceNo和subName进行排序
Collections.sort(relList, new Comparator<Object>() {
    @Override
    public int compare(Object obj1, Object obj2) {
    　　CpPlanSubRel rel1 = (CpPlanSubRel) obj1;
    　　CpPlanSubRel rel2 = (CpPlanSubRel) obj2;
    　　// 首先比较序号，如果序号(sequenceNo)相同，则比较科目名字(subName)
    　　int flag = rel1.getCpSubject().getSequenceNo().compareTo(rel2.getCpSubject().getSequenceNo());
    　　if (flag == 0)
        　　return rel1.getCpSubject().getSubName().compareTo(rel2.getCpSubject().getSubName());
    　　else
   　　　　 return flag;
    }
});