MongoDB - Java - 从数组中检索元素

Question

我是MongoDB的新手，我将它与Java驱动程序一起使用。我有这个文档结构：

{
    "_id" : ObjectId("5598734f96de4e47f61f250c"),

    "restaurant_name" : ["restaurant_1"],

    "menu" : [ 
        "A", 
        "B", 
        "C", 
        "D", 
        "E", 
        "F"
    ]
}

根据这个例子，我想把菜单的所有元素放在一个数组中（用数组的元素做一些事情）并显示它们：

Name: restaurant_1

Menu: A B C D E F

我想对数组的元素做些什么。

Answer 1

import com.mongodb.BasicDBObject;
import com.mongodb.DB;
import com.mongodb.DBCollection;
import com.mongodb.DBCursor;
import com.mongodb.MongoClient;

public class QueryDB {
    static MongoClient clientMongo;

    public static void main(String arg[]) {

        getMenu("restaurant_1");

    }

    private static void getMenu(String restaurant) {
        // TODO Auto-generated method stub
        try {
            clientMongo = new MongoClient();
            DB db = clientMongo.getDB("**DATABASE NAME**");
            DBCollection collectionMongo = db.getCollection("**COLLECTION NAME**");
            DBCursor cursor = collectionMongo.find(new BasicDBObject("menu",
                    restaurant));
            if (cursor.count() == 0)
                System.out.println("No Menu found");
            while (cursor.hasNext()) {
                System.out.println(cursor.next().get("menu"));
            }

        } catch (UnknownHostException e) {
            // TODO Auto-generated catch block
            System.out.println("Could not connect to Database");
            e.printStackTrace();
        }

    }

}