業務邏輯，

查詢符合 ：1、大於且小於時間 2、按atype2欄位篩選  3、按人數字段求和  4、按省欄位聚合

下面程式碼，可以直接拿來用。

public List<DBObject> deathnumberByProvince(String startDate, String endDate,String type2) {

        List<DBObject> optionList = new ArrayList<>();  //mongodb查詢
        BasicDBObject gteMoneyStart = new BasicDBObject("originaltime",new BasicDBObject("$gte", startDate) );
        BasicDBObject matchMoneyStart = new BasicDBObject("$match", gteMoneyStart);
        optionList.add(matchMoneyStart);
        BasicDBObject gteMoneyEnd = new BasicDBObject("originaltime",new BasicDBObject("$lte", endDate) );
        BasicDBObject matchMoneyEnd = new BasicDBObject("$match", gteMoneyEnd);
        optionList.add(matchMoneyEnd);

        BasicDBObject query = new BasicDBObject("atype2", type2);
        BasicDBObject matchProvince = new BasicDBObject("$match", query);
        optionList.add(matchProvince);

        DBObject groupFields=new BasicDBObject();
        groupFields = new BasicDBObject( "_id", "$province");
        groupFields.put("deathnumber", new BasicDBObject( "$sum", "$deathnumber"));
        DBObject group = new BasicDBObject("$group", groupFields);
        optionList.add(group);

        DBCollection collection = MongoDBUtil.getDBCollection("acc");
        List<DBObject> results = (List<DBObject>) collection.aggregate(optionList).results();
        return results;
    }