java中的mongodb问题与限制和排序

Java
import com.MongoDB.MongoClient;
import com.MongoDB.client.MongoCollection;
import com.MongoDB.client.MongoDatabase;
import org.bson.Document;
public class MongoDBExample {
    public static void mAIn(String[] args) {
        // 连接MongoDB数据库
        MongoClient mongoClient = new MongoClient("localhost", 27017);
        // 选择数据库
        MongoDatabase Database = mongoClient.getDatabase("mydb");
        // 选择集合
        MongoCollection<Document> collection = Database.getcollection("mycollection");
        // 查询文档
        Document query = new Document("name", "John");
        Document result = collection.find(query).first();
        System.out.println(result);
        
        // 关闭连接
        mongoClient.close();
    }
}