屬於同一類的另一個對象的對象的訪問屬性

Question

嗨，我對OOP不太好，對不起，如果有人問同樣的問題。 現在我在從另一個對象訪問一個對象的屬性時遇到問題，其中兩個對象都屬於一個對象

public abstract class GameClient (){  
protected ClientRegistry registry;  
..   
}


public class MarketClient extends GameClient {   
public Auctioneer auctioneer = null;  
public Specialist specialist;  
...  
((GenericDoubleAuctioneer) auctioneer).setRegistry((MarketRegistry) registry);
specialist = registry.addSpecialist(clientId);  
}


public class Specialist extends AccountHolder() {  
public Specialist(final String id) {
        this(id, null);  
...   
}


public interface Auctioneer extends QuoteProvider (){  
public MarketRegistry getRegistry();  
public List configuration  
...  }

  public class DailyAssessmentReport(){  
protected void calculateProfits() {  
final Specialist specialists[] = GameController.getInstance().getRegistry().getSpecialists();  
//later, I'll get the ID of each specialist from specialists[];  
...  
...  
public Map< specialistID, List, Score> Result;  
//this Map contains specialistID , auctioneer.configuration, score  
}

我想做的是制作一個包含（specialistID，auctioneer.configuration，profit）的MAP。 我的問題是如何從DailyAssessmentReport類訪問/獲取Auctioneer.configuration價值？

非常感謝您的回答

Answer 1

您可以使用地圖，例如HashMap。 請注意，地圖從一個對象映射到另一對象。 它們不會像您在示例中嘗試的那樣從一個對象映射到另外兩個對象。 但是，您仍然可以通過將兩個目標對象存儲在一個公共容器對象（例如ArrayList或2元素數組）中，然后映射到該容器對象來實現您的目標。 例：

HashMap<String, Object[]> specialistIdToContainerObjectMap = new HashMap<String, Object[]>();

// get two objects which should be looked up later through the map, based on specialist ID
Specialist specialist = ...;
Auctioneer auctioneer = ...;

// create container object to hold the two objects to which we want to map
Object[] containerObject = new Object[2];
containerObject[0] = specialist;
containerObject[1] = auctioneer;

// store the container object in the map
specialistIdToContainerObjectMap.put(specialist.getId(), containerObject);

然后，您可以稍后查找容器對象，並從中提取兩個引用的對象：

// get a specialist id from somewhere, e.g. by doing someSpecialist.getId()
String specialistId = ...;

// look up the container object from the map
Object[] containerObject = specialistIdToContainerObjectMap.get(specialistId);

// extract the specialist and the auctioneer from the container object
Specialist specialist = (Specialist) containerObject[0];
Auctioneer auctioneer = (Auctioneer) containerObject[1];

我希望這可以幫助你。 如果不是，例如因為我誤解了您的問題，請提供反饋，以便我們為您找到合適的解決方案。