在类里面直接写了如下代码：

List<Long> paperID1s = new ArrayList<Long>()
    {
        {
            paperID1s.add(FIRST_STAGE_ID_1);
            paperID1s.add(FIRST_STAGE_ID_2);
            paperID1s.add(FIRST_STAGE_ID_3);
            paperID1s.add(FIRST_STAGE_ID_4);
            paperID1s.add(FIRST_STAGE_ID_5);
            paperID1s.add(FIRST_STAGE_ID_6);
            paperID1s.add(FIRST_STAGE_ID_6);
        }
    };

导致服务器503错误，报构造什么的空指针的错误