java - 面向对象设计 - 法术

Question

我的第一个 Java 项目是一个基本的角色扮演游戏。现在我在研究法术，我需要一些 OOD 指导。

我有Character，它是一个抽象类。 Character 有一些子类(比如mage、fighter、rogue、牧师).

法师和牧师(至于现在，牧师没有法力，但它可能会改变) 都是施法者。

我还有一个 Spell 类，其中包含一些信息(例如 spell name、mana cost 等)。 MageSpellsList 和 ClericSpellsList 是另外两个类，它们都有 Spell 类列表。我也有 Effects 类(施法应该使用它)。

什么是处理法术的良好面向对象设计(解决方案不应包括 Effects 类，我可以稍后处理)？

也许使用“SpellCaster”接口(interface)和一些方法，如 castSpell 和 showSpellbook，这样 Mage 和 Cleric 将实现该接口(interface)？ .

也许 MageSpellsList 和 ClericSpellsList 应该是 Spell 的子类？我的目

法师.java:

public class Mage extends Character {

    private List<Spell> spellBook;
    private int mana;
    private int CurrentMana;

    public Mage(String name) {

        super(name);

        setName(name);
        setCharacterClass("Mage");
        setLevel(1);
        setHitDice(4);

        setStrength(10);
        setConstitution(10);
        setDexterity(14);
        setIntelligence(16);
        setWisdom(14);
        setCharisma(10);

        setHp((int) (4 + getModifier(getConstitution())));
        setCurrentHp(getHp());
        setArmorClass(10 + getModifier(getDexterity()));
        setBaseAttackBonus(0);

        setMana(20 + 2 * getModifier(getIntelligence()));
        setCurrentMana(getMana());
        spellBook = new ArrayList<Spell>();

    }

    public int getMana() {
        return mana;
    }

    public int getCurrentMana() {
        return CurrentMana;
    }

    protected void setMana(int mna) {
        mana = mna;
    }

    protected void setCurrentMana(int CurrMana) {
        CurrentMana = CurrMana;
    }

    public void showSpellBook() {

        for (Iterator<Spell> iter = spellBook.iterator(); iter.hasNext(); ) {
            Spell spell = iter.next();
            System.out.println("Spell name: " + spell.getSpellName());
            System.out.println("Spell effect: " + spell.getEffect());
        }
    }

    public void addToSpellBook(String spellName) {

        Spell newSpell;
        newSpell = MageSpellsList.getSpell(spellName);
        spellBook.add(newSpell);
        System.out.println(newSpell.getSpellName() + " has been added to the spellbook");

    }


    public void chooseSpells() {
        System.out.println();
    }

    void castSpell(String spellName, Character hero, Character target) {
        try {
            Spell spell = MageSpellsList.getSpell(spellName);
            System.out.println("You casted: " + spellName);
            System.out.println("Spell effect: " + spell.getEffect());
        } catch (Exception e) {
            System.out.println("No such spell");
        }
    }
}

拼写.java:

public class Spell {
    private String name;
    private int spellLevel;
    private String effect;
    private int manaCost;
    private int duration;

    Spell(String name, int spellLevel, String effect, int manaCost, int duration) {
        this.name = name;
        this.spellLevel = spellLevel;
        this.effect = effect;
        this.manaCost = manaCost;
        this.duration= duration;
    }

    String getSpellName() { return name; }

    int getSpellLevel() { return spellLevel; }

    String getEffect() { return effect; }

    int getManaCost() {
        return manaCost;
    }

    int getDuration() { return  duration; }
}

MageSpellsList.java:

public class MageSpellsList {
    static List<Spell> MageSpellsList = new ArrayList<Spell>();

    static {
        MageSpellsList.add(new Spell("Magic Missiles", 1, "damage", 2, 0));
        MageSpellsList.add(new Spell("Magic Armor", 1, "changeStat", 2, 0));
        MageSpellsList.add(new Spell("Scorching Ray ", 2, "damage", 4, 0));
        MageSpellsList.add(new Spell("Fireball", 3, "damage", 5,0 ));
        MageSpellsList.add(new Spell("Ice Storm", 4, "damage", 8, 0));
    }

    static void  showSpellsOfLevel(int spellLevel) {
        try {
            for (Iterator<Spell> iter = MageSpellsList.iterator(); iter.hasNext(); ) {
                Spell spell = iter.next();
                if (spellLevel == spell.getSpellLevel()) {
                    System.out.println("Spell name: " + spell.getSpellName());
                    System.out.println("Spell effect: " + spell.getEffect());
                }
            }
        } catch (Exception e){
            System.out.println("Epells of level " + spellLevel + " haven't been found in spells-list");
        }
    }

    static Spell getSpell(String spellName) {
        try {
            for (Iterator<Spell> iter = MageSpellsList.iterator(); iter.hasNext(); ) {
                Spell spell = iter.next();
                if (spellName.equals(spell.getSpellName())) {
                    return spell;
                }
            }
        } catch (Exception e){
            System.out.println(spellName + " haven't been found in spells-list");
            return null;
        }
        return null;
    }
}

效果.java:

public class Effects {

    public  void  damage(int dice, Character attacker, Character target){

        int damage = DiceRoller.roll(dice);
        System.out.println(attacker.getName() + " dealt " + damage + " damage to " + target.getName());
        target.setCurrentHp(target.getCurrentHp() - damage);
    }

    public static void damage(int n, int dice, int bonus, Character target) {

        int damage = DiceRoller.roll(n,dice,bonus);
        System.out.println("You dealt" + damage + "damage to " + target.getName());
        target.setCurrentHp(target.getCurrentHp() - damage);
    }

    public static void heal(int n, int dice, int bonus, Character target) {

        int heal = DiceRoller.roll(n,dice,bonus);
        if (heal + target.getCurrentHp() >= target.getHp()) {
            target.setCurrentHp(target.getHp());
        } else {
            target.setCurrentHp(target.getCurrentHp() + heal);
        }

        System.out.println("You healed" + heal + " hit points!");
    }

    public static void changeStat(String stat, int mod, Character target){

        System.out.println(stat + " + " + mod);

        switch (stat) {
            case "strength":
                target.setStrength(target.getStrength() + mod);
                break;
            case "constitution":
                target.setConstitution(target.getConstitution() + mod);
                break;
            case "dexterity":
                target.setDexterity(target.getDexterity() + mod);
                break;
            case "intelligence":
                target.setIntelligence(target.getIntelligence() + mod);
                break;
            case "wisdom":
                target.setWisdom(target.getWisdom() + mod);
                break;
            case "charisma":
                target.setCharisma(target.getCharisma() + mod);
                break;
            case "armorClass":
                target.setArmorClass(target.getArmorClass() + mod);
                break;
        }
    }
}

Answer 1

序言

我尽量概括类，这样我就不会得到很多只代表不同数据而不是不同结构的特定类。此外，我尝试将数据结构与游戏机制分开。特别是，我尝试将战斗机制全部放在一个地方，而不是将它们分成不同的类别，并且我尝试不对任何数据进行硬编码。在这个答案中，我们将介绍角色、他们的能力/法术、能力的效果，以及战斗机制.

字符

例如，考虑一个代表您角色的 PlayableCharacter。这是一个标准的数据类。它提供了增加或减少生命值和法力值的方法，以及可用能力的集合。

class PlayableCharacter {
    private final int maxHealth;
    private int health;
    private final int maxResource;    // mana, energy and so on
    private int resource;
    private final Collection<Ability> abilities;

    // getters and setters
}

能力

能力同样是数据类。它们代表法术力成本、触发效果等。我经常将其表示为一个普通类，然后从外部数据文件中读取个人能力。在这里我们可以跳过它并用枚举声明它们。

enum Ability {
    FIREBALL("Fireball", 3, 5, new Effect[] {
        new Effect(Mechanic.DAMAGE, 10, 0),
        new Effect(Mechanic.BURN, 2, 3)
    });

    private final String name;
    private final int level;
    private final int cost;
    private final List<Effect> effects;
}

效果

最后，效果说明了一个能力的作用。伤害有多大，持续多长时间，对角色有何影响。同样，这都是数据，没有游戏逻辑。

class Effect {
    private final Mechanic effect;
    private final int value;
    private final int duration;
}

机制只是一个枚举。

enum Mechanic {
    DAMAGE, BURN;
}

力学

现在是时候让事情正常进行了。这是您的游戏循环将与之交互的类，您必须向它提供游戏状态(例如哪些角色正在战斗)。

class BattleEngine {
    void useAbility(PlayableCharacter source, PlayableCharacter target, Ability ability) {
        // ...
    }
}

如何实现每个机制取决于您。它的范围可以是每个 Mechanic 的 hell 开关或 if/else，或者您可以将代码移动到 Mechanic 枚举，或者移动到私有(private)嵌套类并使用 EnumMap 以检索每个处理程序。

示例机制

interface MechanicHandler {
    void apply(PlayableCharacter source, PlayableCharacter target, Effect effect);
}

class BattleEngine {
    private final Map<Mechanic, MechanicHandler> mechanics;

    void useAbility(PlayableCharacter source, PlayableCharacter target, Ability ability) {
        source.decreaseResource(ability.getCost());
        for (Effect effect: ability.getEffects()) {
            MechanicHandler mh = mechanics.get(e.getMechanic());
            mh.apply(source, target, effect);
        }
    }

    private static final class DicePerLevel implements MechanicHandler {
        @Override
        public void apply(PlayableCharacter source, PlayableCharacter target, Effect effect) {
            int levels = Math.min(effect.getValue(), source.getLevel());
            int damage = 0;
            for (int i = 0; i < levels; ++i) {
                int roll; // roll a d6 die
                damage += roll;
            }
            target.decreaseHealth(damage);
        }
    }
}