构造器模式

news2024/11/17 5:42:09

构造器模式

意图
- 将一个复杂对象的构建和表示分离，使得相同的构建能创建不同的表示。
解释

案例：想象一个角色扮演游戏的特征生成器。最简单的选择是让计算机为你创建角色。如果你想手动选择特征的细节像职业、性别、头发的颜色等。特征的产生是一个循序渐进的过程，当所有选择都就绪时结束。

简单说：允许你在避免函数污染的情况下创建不同特征的对象。当一个对象有好几种特征时或当创建对象需要很多步骤时。

样例

//盔甲
public enum Armor {
    CHAIN_MAIL("Chain Mail"),
    CLOTHES("Clothes"),
    LEATHER("leather"),
    PLATE("plate");

    private String description;

    Armor(String description) {
        this.description = description;
    }

    public String getDescription() {
        return description;
    }
}

//头发的颜色
public enum HairColor {
    BLACK,
    BLOND,
    BROWN,
    RED,
    WHITE;
}

//头发类型
public enum HairType {
    BALD("bald"),
    CURLY("curly"),
    LONG_CURLY("long curly"),
    LONG_STRAIGHT("long straight"),
    SHORT("short");

    private String description;


    HairType(String description) {
        this.description = description;
    }
}

//职业
public enum Profession {
    MAGE,
    PRIEST,
    THIEF,
    WARRIOR;
}

//武器
public enum Weapon {
    AXE,
    BOW,
    DAGGER,
    SWORD,
    WARHAMMER;

}

//角色
public final class Hero {
    private Armor armor;
    private Weapon weapon;
    private HairType hairType;
    private HairColor hairColor;
    private Profession profession;

    public Hero(Builder builder){
        this.armor = builder.armor;
        this.weapon = builder.weapon;
        this.hairType = builder.hairType;
        this.hairColor = builder.hairColor;
        this.profession = builder.profession;
    }

    public Armor getArmor() {
        return armor;
    }

    public Weapon getWeapon() {
        return weapon;
    }

    public HairType getHairType() {
        return hairType;
    }

    public HairColor getHairColor() {
        return hairColor;
    }

    public Profession getProfession() {
        return profession;
    }

    public static class Builder {
        private Armor armor;
        private HairType hairType;
        private HairColor hairColor;
        private Profession profession;
        private Weapon weapon;
        private String name;

        public Builder(Profession profession, String name) {
            this.profession = profession;
            this.name = name;
        }

        public Hero build() {
            return new Hero(this);
        }

        Builder withArmor(Armor armor) {
            this.armor = armor;
            return this;
        }

        Builder withHairType(HairType hairType) {
            this.hairType = hairType;
            return this;
        }

        Builder withHairColor(HairColor hairColor) {
            this.hairColor = hairColor;
            return this;
        }

        Builder withWeapon(Weapon weapon) {
            this.weapon = weapon;
            return this;
        }
    }

}

public class Main {
    public static void main(String[] args) {
        var riobard = new Hero.Builder(Profession.MAGE, "Riobard").
                withHairColor(HairColor.BLACK).
                withWeapon(Weapon.DAGGER)
                .build();
        
    }
}