设计模式——组合模式

package net.dp.composite.menu;


public abstract class MenuComponent {
   
	public void add(MenuComponent menuComponent) {
		throw new UnsupportedOperationException();
	}
	public void remove(MenuComponent menuComponent) {
		throw new UnsupportedOperationException();
	}
	public MenuComponent getChild(int i) {
		throw new UnsupportedOperationException();
	}
  
	public String getName() {
		throw new UnsupportedOperationException();
	}
	public String getDescription() {
		throw new UnsupportedOperationException();
	}
	public double getPrice() {
		throw new UnsupportedOperationException();
	}
	public boolean isVegetarian() {
		throw new UnsupportedOperationException();
	}
  
	public void print() {
		throw new UnsupportedOperationException();
	}
}

package net.dp.composite.menu;

import java.util.Iterator;
import java.util.ArrayList;

public class Menu extends MenuComponent {
	ArrayList<MenuComponent> menuComponents = new ArrayList<MenuComponent>();
	String name;
	String description;

	public Menu(String name, String description) {
		this.name = name;
		this.description = description;
	}

	public void add(MenuComponent menuComponent) {
		menuComponents.add(menuComponent);
	}

	public void remove(MenuComponent menuComponent) {
		menuComponents.remove(menuComponent);
	}

	public MenuComponent getChild(int i) {
		return (MenuComponent) menuComponents.get(i);
	}

	public String getName() {
		return name;
	}

	public String getDescription() {
		return description;
	}

	public void print() {
		System.out.print("\n" + getName());
		System.out.println(", " + getDescription());
		System.out.println("---------------------");

		Iterator<MenuComponent> iterator = menuComponents.iterator();
		while (iterator.hasNext()) {
			MenuComponent menuComponent = iterator.next();
			menuComponent.print();
		}
	}
}

package net.dp.composite.menu;

public class MenuItem extends MenuComponent {
	String name;
	String description;
	boolean vegetarian;
	double price;

	public MenuItem(String name, String description, boolean vegetarian,
			double price) {
		this.name = name;
		this.description = description;
		this.vegetarian = vegetarian;
		this.price = price;
	}

	public String getName() {
		return name;
	}

	public String getDescription() {
		return description;
	}

	public double getPrice() {
		return price;
	}

	public boolean isVegetarian() {
		return vegetarian;
	}

	public void print() {
		System.out.print("  " + getName());
		if (isVegetarian()) {
			System.out.print("(v)");
		}
		System.out.println(", " + getPrice());
		System.out.println("     -- " + getDescription());
	}
}

package net.dp.composite.menu;
  
public class Waitress {
	MenuComponent allMenus;
 
	public Waitress(MenuComponent allMenus) {
		this.allMenus = allMenus;
	}
 
	public void printMenu() {
		allMenus.print();
	}
}

package net.dp.composite.menu;

public class MenuTestDrive {
	public static void main(String args[]) {
		MenuComponent pancakeHouseMenu = new Menu("PANCAKE HOUSE MENU",
				"Breakfast");
		MenuComponent dinerMenu = new Menu("DINER MENU", "Lunch");
		MenuComponent cafeMenu = new Menu("CAFE MENU", "Dinner");
		MenuComponent dessertMenu = new Menu("DESSERT MENU",
				"Dessert of course!");
		MenuComponent coffeeMenu = new Menu("COFFEE MENU",
				"Stuff to go with your afternoon coffee");

		MenuComponent allMenus = new Menu("ALL MENUS", "All menus combined");

		allMenus.add(pancakeHouseMenu);
		allMenus.add(dinerMenu);
		allMenus.add(cafeMenu);

		pancakeHouseMenu.add(new MenuItem("K&B‘s Pancake Breakfast",
				"Pancakes with scrambled eggs, and toast", true, 2.99));
		pancakeHouseMenu.add(new MenuItem("Regular Pancake Breakfast",
				"Pancakes with fried eggs, sausage", false, 2.99));
		pancakeHouseMenu.add(new MenuItem("Blueberry Pancakes",
				"Pancakes made with fresh blueberries, and blueberry syrup",
				true, 3.49));
		pancakeHouseMenu.add(new MenuItem("Waffles",
				"Waffles, with your choice of blueberries or strawberries",
				true, 3.59));

		dinerMenu.add(new MenuItem("Vegetarian BLT",
				"(Fakin‘) Bacon with lettuce & tomato on whole wheat", true,
				2.99));
		dinerMenu.add(new MenuItem("BLT",
				"Bacon with lettuce & tomato on whole wheat", false, 2.99));
		dinerMenu.add(new MenuItem("Soup of the day",
				"A bowl of the soup of the day, with a side of potato salad",
				false, 3.29));
		dinerMenu
				.add(new MenuItem(
						"Hotdog",
						"A hot dog, with saurkraut, relish, onions, topped with cheese",
						false, 3.05));
		dinerMenu.add(new MenuItem("Steamed Veggies and Brown Rice",
				"Steamed vegetables over brown rice", true, 3.99));

		dinerMenu
				.add(new MenuItem(
						"Pasta",
						"Spaghetti with Marinara Sauce, and a slice of sourdough bread",
						true, 3.89));

		dinerMenu.add(dessertMenu);

		dessertMenu.add(new MenuItem("Apple Pie",
				"Apple pie with a flakey crust, topped with vanilla icecream",
				true, 1.59));

		dessertMenu.add(new MenuItem("Cheesecake",
				"Creamy New York cheesecake, with a chocolate graham crust",
				true, 1.99));
		dessertMenu.add(new MenuItem("Sorbet",
				"A scoop of raspberry and a scoop of lime", true, 1.89));

		cafeMenu
				.add(new MenuItem(
						"Veggie Burger and Air Fries",
						"Veggie burger on a whole wheat bun, lettuce, tomato, and fries",
						true, 3.99));
		cafeMenu
				.add(new MenuItem("Soup of the day",
						"A cup of the soup of the day, with a side salad",
						false, 3.69));
		cafeMenu.add(new MenuItem("Burrito",
				"A large burrito, with whole pinto beans, salsa, guacamole",
				true, 4.29));

		cafeMenu.add(coffeeMenu);

		coffeeMenu.add(new MenuItem("Coffee Cake",
				"Crumbly cake topped with cinnamon and walnuts", true, 1.59));
		coffeeMenu.add(new MenuItem("Bagel",
				"Flavors include sesame, poppyseed, cinnamon raisin, pumpkin",
				false, 0.69));
		coffeeMenu.add(new MenuItem("Biscotti",
				"Three almond or hazelnut biscotti cookies", true, 0.89));

		Waitress waitress = new Waitress(allMenus);

		waitress.printMenu();
	}
}