Zuul世界 - 使用ArrayList添加项目

Question

我目前正在努力改善＆＃34; Zuul世界＆＃34;使用BlueJ。我正在进行Item课程，并在那里放了几个项目。下一步是将项目放入房间，我认为这是我面临的当前问题：您如何引用或使用在另一个类中建立的ArrayList？希望如果我能理解这是怎么做的，那么我可以研究如何在特定的房间里放置一个或多个特定物品。

任何帮助都将不胜感激。

请参阅下面的代码：

Item类

public Item(String itemDescription, int itemWeight)
{
    // initialise instance variables
    itemDescription = itemDescription;
    itemWeight = itemWeight;
    this.list = new ArrayList<Item>();
    Item item = new Item(itemDescription, itemWeight);

}
/**
 * Name of item
 */
public String getItemDescription()
{
    return itemDescription;
}
/**
 * Weight of an Item
 */
public int itemWeight()
{
    return itemWeight;
}

/**
 * Show items 
 */
public ArrayList<Item> getItems ()
{
    return list;
}
public String getItemString()
{
    String returnString = "Item:";
    {
        returnString += ""+list;
    }
    return returnString;
}
/**
 * Presents name and weight of item
 */
public String toString()
{
    return "Item: " + itemDescription + "Weight " + itemWeight;
}
/**
 * List of items
 */
public void addItem()
{
    list.add(new Item("can of coke",1));
    list.add(new Item("bike",6));
    list.add(new Item("textbook",4)); 
    list.add(new Item("£20 note",1));
    list.add(new Item("stick",2));
    list.add(new Item("Theater leaflet",1));
    list.add(new Item("mobile phone",2));
}

Room课程

public class Room 
{
    private String description;
    private HashMap<String, Room> exits;

    public Room(String description) 
    {
        this.description = description;

    }

    /**
     * Define the exits of this room.  Every direction either leads
     * to another room or is null (no exit there).
     * @param north The north exit.
     * @param east The east east.
     * @param south The south exit.
     * @param west The west exit.
     */
    public void setExit(String direction, Room neighbor) 
    {
        exits.put(direction, neighbor);
    }

    public Room getExit(String direction)
    {
        return exits.get(direction);
    }

    /**
     * @return The description of the room.
     */
    public String getDescription()
    {
        return description;
    }

    /**
     * Return a long description of this room, of the form;
     *  You are in the kitchen.
     *  Exits: north west
     *  @return A description of the room, including exits.
     */
    public String getLongDescription()
    {
        return "You are" + description + "./n" +getExitString();
    }

    /**
     * Return a description of the room's exits,
     * for example, "Exits: north west".
     * @return A description of the available exits.
     * 
     */
    public String getExitString()
    {
        String returnString = "Exits:";
        Set<String> keys = exits.keySet();
        for(String exit :keys) {
            returnString += "" + exits;
        }
        return returnString;
    }

}