A Little Java, A Few Patterns: Come to Our Carousel

// 访问者 
class OnlyOnionsV {
    boolean forSkewer() {
        return true;
    }
    boolean forOnion(ShishD s) {
        return s.onlyOnions();
    }
    boolean forLamb(ShishD s) {
        return false;
    }
    boolean forTomato(ShishD s) {
        return false;
    }
}

class IsVegetarianV {
    boolean forSkewer() {
        return ture;
    }
    boolean forOnion(ShishD s) {
        return s.IsVegetarian();
    }
    boolean forLamb(ShishD s) {
        return false;
    }
    boolean forTomato(ShishD s) {
        return s.IsVegetarian();
    }
}

// 使用访问者模式的 ShishD
// 这里可以对比一下第二章节的 ShishD 代码 
abstract class ShishD { // 羊肉 
    OnlyOnionsV ooFn = new OnlyOnionsV();
    IsVegetarianV ivFn = new IsVegetarianV();
    abstract boolean onlyOnions();
    abstract boolean IsVegetarian();
}

class Skewer extends ShishD { // 串 
    boolean onlyOnions() {
        return ooFn.forSkewer();
    }
    boolean IsVegetarian() {
        return ivFn.forSkewer();
    }
}

class Onion extends ShishD { // 洋葱 
    ShishD s;
    Onion (ShishD _s) {
        s = _s;
    }
    boolean onlyOnions() {
        return ooFn.forOnion(s);
    }
    boolean IsVegetarian() {
        return ivFn.forOnion(s);
    }
}

class Lamb extends ShishD { // 羔羊肉 
    ShishD s;
    Lamb (ShishD _s) {
        s = _s;
    }
    boolean onlyLambs() {
        return ooFn.forLamb(s);
    }
    boolean IsVegetarian() {
        return ivFn.forLamb(s);
    }
}

class Tomato extends ShishD { // 西红柿 
    ShishD s;
    Tomato (ShishD _s) {
        s = _s;
    }
    boolean onlyTomatos() {
        return ooFn.forTomato(s);
    }
    boolean IsVegetarian() {
        return ivFn.forTomato(s);
    }
}

abstract class PizzaD { // 披萨饼 
    RemAV remFn = new RemAV();
    TopAwCV topFn = new TopAwCV();
    SubAbCV subFn = new SubAbCV();
    abstract PizzaD remA();
    abstract PizzaD topAwC();
    abstract PizzaD subAbC();
}

class Crust extends PizzaD { // 面包皮 
    PizzaD remA() {
        return remFn.forCrust();
    }
    PizzaD topAwC() {
        return topFn.forCrust();
    }
    PizzaD subAbC() {
        return subFn.forCrust();
    }
}

class Cheese extends PizzaD { // 奶酪 
    PizzaD p;
    Cheese(PizzaD _p) {
        p = _p;
    }
    PizzaD remA() {
        return remFn.forCheese(p);
    }
    PizzaD topAwC() {
        return topFn.forCheese(p);
    }
    PizzaD subAbC() {
        return subFn.forCheese(p);
    }

}

Classr Olive extends PizzaD { // 橄榄 
    PizzaD p;
    Olive(PizzaD _p) {
        p = _p;
    }
    PizzaD remA() {
        return remFn.forOlive(p);
    }
    PizzaD topAwC() {
        return topFn.forOlive(p);
    }
    PizzaD subAbC() {
        return subFn.forOlive(p);
    }
}

class Anchovy extends PizzaD { // 凤尾鱼 
    PizzaD p;
    Anchovy(PizzaD _p) {
        p = _p;
    }
    PizzaD remA() {
        return remFn.forAnchovy(p);
    }
    PizzaD topAwC() {
        return topFn.forAnchovy(p);
    }
    PizzaD subAbC() {
        return subFn.forAnchovy(p);
    }
}

class Sausage extends PizzaD { // 香肠 
    PizzaD p;
    Sausage(PizzaD _p) {
        p = _p;
    }
    PizzaD remA() {
        return remFn.forSausage(p);
    }
    PizzaD topAwC() {
        return topFn.forSausage(p);
    }
    PizzaD subAbC() {
        return subFn.forSausage(p);
    }
}

class RemAV {
    PizzaD forCrust() {
        return new Crust();
    }
    PizzaD forCheese(PizzaD p) {
        return new Cheese(p.remA());
    }
    PizzaD forOlive(PizzaD p) {
        return new Olive(p.remA());
    }
    PizzaD forAnchovy(PizzaD p) {
        return p.remA();
    }
    PizzaD forSausage(PizzaD p) {
        return new Sausage(p.remA());
    }
}

class TopAwCV {
    PizzaD forCrust() {
        return new Crust();
    }
    PizzaD forCheese(PizzaD p) {
        return new Cheese(p.topAwC());
    }
    PizzaD forOlive(PizzaD p) {
        return new Olive(p.topAwC());
    }
    PizzaD forAnchovy(PizzaD p) {
        return new Cheese(new Anchovy(p.topAwC()));
    }
    PizzaD forSausage(PizzaD p) {
        return new Sausage(p.topAwC());
    }
}

class SubAbCV {
    PizzaD forCrust() {
        return new Crust();
    }
    PizzaD forCheese(PizzaD p) {
        return new Cheese(p.subAbC());
    }
    PizzaD forOlive(PizzaD p) {
        return new Olive(p.subAbC());
    }
    PizzaD forAnchovy(PizzaD p) {
        return new Cheese(p.subAbC());
    }
    PizzaD forSausage(PizzaD p) {
        return new Sausage(p.subAbC());
    }
}