在OOP中，如何构造玩家项目的玩家项目？

Question

我想制作一个小型RPG游戏，该游戏既要有商店，又要有玩家库存。我的问题是，如何构造游戏中可用的物品。为每个商品都具有一个类，或者仅是一个可以代表任何类型商品的商品类，这会很好吗？我目前只有一个可以创建所有类型项目的项目类，但是，它的执行方式并不理想。

我目前有一个Item类，这是创建项目时使用的类。还有一个Items类，可将所有项目作为一个整体进行管理。例如显示商店中所有可用的物品，可放下的物品等。

public class Items {

    public static Items _session = null;
    private ArrayList<Item> items = new ArrayList<Item>();
    private double[] itemWeights = {
            0.1,
            0.1,
            0.1,
            0.1
    };
    private String[] itemNames = {
            "Ship Part",
            "Health Potion",
            "Strength Potion",
            "Lucky Potion"
    };

    private String[] itemDescriptions = {
            "Replacing one of the ships missing parts",
            "Returning health to a crew member",
            "Increasing the max health of a crew memnber",
            "Increasing the amount of items found through a single planet search"
    };

    private String[] itemStats = {
            "Ship parts repaired + 1",
            "Crew member health + 5% max health",
            "Crew member max health + 10",
            "Item drop + 1, (does not stack)"
    };

    private int[] itemCosts = {
            10,
            10,
            10,
            10
    };

    private Items() {
        int i = 0;
        while(i < itemNames.length) {
            Item temp = new Item(itemNames[i], itemWeights[i], itemDescriptions[i], itemStats[i], itemCosts[i]);
            items.add(temp);
            i += 1;
        }

    }

    public static Items getInstance() {
        if(_session == null) {
            _session = new Items();
        }
        return _session;
    }

    public void presentItems() {
        System.out.println(); // Empty line to make content more readable

        int currentPosition = 1;
        for (Item item: items) {
            String temp = String.format("%s. %s", currentPosition, item);
            System.out.println(temp);
            currentPosition ++;
        }
    }

    public ArrayList<Item> getItems() {
        return this.items;
    }

    public Item getItem(int index) {
        return items.get(index);
    }

}

public class Item {

    private String name;
    private double dropChance;
    private String description;
    private String stats;
    private int cost;
    private int count = 1;

    /**
     * Constructor for an Item object
     * @param itemName Describes the items name.
     * @param itemChance Describes the random chance the item has to drop.
     * @param itemDescription Describes what the items does or is used for.
     * @param itemStats Describes the exact affects the item will have when used.
     */
    public Item(String itemName, double itemChance, String itemDescription, String itemStats, int itemCost) {
        name = itemName;
        dropChance = itemChance;
        description = itemDescription;
        stats = itemStats;
        cost = itemCost;
    }

    /**
     * Get the name of the current Item object.
     * @return Will return a String representing the name of the item.
     */
    public String getName() {
        return this.name;
    }

    /**
     * Get the drop chance of the current Item object.
     * @return Will return a double value representing the drop chance of the item.
     */
    public double getDropChance() {
        return this.dropChance;
    }

    /**
     * Get the description of the current Item object.
     * @return Will return a String representing the description of the item.
     */
    public String getDescription() {
        return this.description;
    }

    /**
     * Get the stats of the current Item object.
     * @return Will return a String representing the stats of the item.
     */
    public String getStats() {
        return this.stats;
    }

    /**
     * Get the cost of the current Item object.
     * @return Will return an Integer value representing the cost of the item.
     */
    public int getCost() {
        return this.cost;
    }

    /**
     * Get the amount of this item.
     * @return An integer representing the amount of this item.
     */
    public int getCount() {
        return this.count;
    }

    /**
     * Add 1 to the amount of this item.
     */
    public void addCount() {
        this.count += 1;
    }

    /**
     * Deduct 1 from the amount of this item.
     */
    public void deductCount() {
        this.count -= 1;
    }

    /**
     * Overrides the java.lang.Object.toString method to return a descriptive String of the object.
     */
    @Override
    public String toString() {
        String temp = String.format("(%sX) %s...can be used for %s...it's affects are: %s...Costs %s Coins", count, name, description, stats, cost);
        return temp;
    }

}