将list按指定大小分为n组

public static <T> List<List<T>> splitList(List<T> list,int groupSize){
    List<List<T>> result = Lists.newArrayList();
    int length = list.size();
    //每组大小
    StringBuilder stringBuilder = null;
    if (length > groupSize){


        int lastIndex = 0;
        int fromIndex = 0;
        int endIndex = 0;
        //计算分多少组
        int num = (length + groupSize -1 ) / groupSize;
        for(int i = 0;i<num;i++){
            //第i组的起始index
            fromIndex = i *groupSize;
            //第i组的结束index
            endIndex = (i+1) * groupSize < length ? (i+1) * groupSize : length;

            List<T> tempList = Lists.newArrayList();
            for (int j = fromIndex;j<endIndex;j++){
                tempList.add(list.get(j));
            }


            result.add(tempList);
        }
    }else{
        result.add(list);
    }
    return result;
}