바리스타

package coffee;

import java.util.List;

public class Barista {
    private Menu m;
    private List<String> item;

    public Barista(List<String> item) {
        this.item = item;
    }

    // 아메리카노, 카푸치노, 마끼아또, 에스프레소
    public String choose(String name) {
        for (String each : item) {
            if (each.equals(name)) {
                return each;
            }
        }
        return null;
    }

    public String makeCoffee(String m) {
        return m;
    }
}

커피

package coffee;

public class Coffee {
    private String name;
    private int price;

    public Coffee(String menuItem) {
        this.name = menuItem;
    }
}

메인

package coffee;

import java.util.ArrayList;
import java.util.List;

public class CoffeeApp {
    public static void main(String[] args) {
        List<String> l = new ArrayList<>();
        l.add("아메리카노");
        l.add("카푸치노");
        l.add("카라멜마끼아또");
        l.add("에스프레소");

        Barista barista = new Barista(l);
        Customer customer = new Customer(barista);
        customer.order(l, barista);
        String a = barista.makeCoffee(l.get(0));
        System.out.println(a);
    }
}

손님

package coffee;

import java.util.List;

public class Customer {
    private Barista barista;

    public Customer(Barista barista) {
        this.barista = barista;
    }

    public void order(List<String> m, Barista barista) {
        barista.choose(m.get(0));
    }
}

메뉴

package coffee;

import java.util.List;

public class Menu {
    private List<String> item;

    public Menu(List<String> item) {
        this.item = item;
    }
}

메뉴아이템

package coffee;

public class MenuItem {
    private String name;

    public MenuItem(String name) {
        this.name = name;
    }

    public String getName() {
        return this.name;
    }
}