如何在mongodb java中检索具有值的单个键

Question

实施例： 如果我在我的程序中给出姓名，我还需要获得相应年龄的年龄{“姓名”：“msr”，“年龄”：24}喜欢这些

package mongojava;

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

public class javaconn {

    public static void main(String[] args) {


        MongoClient client = new MongoClient("localhost",27017); 
        DB db = client.getDB( "admin" );
        DBCollection collection = db.getCollection("admin");
        DBObject dbo = collection.findOne();
        //String name = (String) dbo.get("Name");
        //String age = (String) dbo.get("age");
        BasicDBObject query = new BasicDBObject();
        query.put("Name", "Siddareddy");
        DBCursor cursor = collection.find(dbo);


        BasicDBObject newDocument = new BasicDBObject();
        newDocument.put("age", "24");
        while (cursor.hasNext()) {
            System.out.println(cursor.next());
        }
    }

}

Answer 1

尝试使用以下查询

Document doc = collection.find(eq("Name", "Siddareddy")).first();