DBObject 列表 - Mongo Java 驱动程序答案

【问题标题】：Lists of DBObjects - Mongo Java DriverDBObject 列表 - Mongo Java 驱动程序
【发布时间】：2014-02-18 07:50:51
【问题描述】：

我正在制作一个游戏，其中在不同的多人服务器中有工具包。玩家可以购买套件，并将其保存到 Mongo 数据库中。我希望数据库的格式如下：

{
    "server": "the_server_name",
    "players": {
        {
            "player": "the_players_username",
            "kits": [
                "kit1",
                "kit3"
            ]
        },
        {
            "player": "the_players_username",
            "kits": [
                "kit1",
                "kit2"
            ]
        }
    }
}

我尝试过这样做，但无济于事。有人愿意为初学者提供一些关于如何实现这一目标的帮助吗？谢谢！

【问题讨论】：

标签： java list mongodb driver dbobject

【解决方案1】：

这是一个简单的例子：

import com.mongodb.*;

public class MongoTest {

    public static void main(String[] args) throws Exception {
        MongoClient mongoClient = new MongoClient("localhost", 27017);
        DB db = mongoClient.getDB("myGameDB");
        DBCollection gameCollection = db.getCollection("myGameCollection");
        BasicDBObject obj = new BasicDBObject().append("sever", "the_server_name");
        BasicDBList players = new BasicDBList();
        BasicDBList list1 = new BasicDBList();
        BasicDBList list2 = new BasicDBList();
        list1.addAll(java.util.Arrays.asList(new String[]{"kit1", "kit2"}));
        list2.addAll(java.util.Arrays.asList(new String[]{"kit1", "kit2"}));
        BasicDBObject playerObj1 = new BasicDBObject("player", "the_players_username").append("kits", list1);
        BasicDBObject playerObj2 = new BasicDBObject("player", "the_players_username").append("kits", list2);
        players.add(playerObj1);
        players.add(playerObj2);
        obj.append("players", players);
        gameCollection.insert(obj);
        printCollectionContent(gameCollection);
    }


    static void printCollectionContent(DBCollection coll) {
        BasicDBObject query = new BasicDBObject();
        BasicDBObject fields = new BasicDBObject("server", true).append("_id", false).append("players",true);
        DBCursor curs = coll.find(query);
        while (curs.hasNext()) {
            DBObject o = curs.next();
            System.out.println(o.toString());
        }
        curs = coll.find(query, fields);
        while (curs.hasNext()) {
            DBObject o = curs.next();
            System.out.println(o.toString());
        }
    }
}

顺便说一句，您的 json 实际上是无效的。 Players 似乎是一个数组，但它缺少 [ ]

本示例使用驱动程序版本2.11.3。示例是为大家展示如何使用驱动，省略了异常处理。

【讨论】：