Design patterns exercise: decorator, simple factory

SandwichShop.java

package be.ac.vub.patterns;

public class SandwichShop {

	public static interface Sandwich {
		public double getPrice();
		public String[] getIngredients();
	}

	public static class CheeseSandwich implements Sandwich {
		@Override
		public double getPrice() {return 2;}
		@Override
		public String[] getIngredients() {return new String[]{"bread", "cheese"};}
	}

	public static class CheeseMayoSandwich implements Sandwich {
		@Override
		public double getPrice() {return 2.5;}
		@Override
		public String[] getIngredients() {return new String[]{"bread", "cheese", "mayonnaise"};}
	}

	public static class CheeseVegetableSandwich implements Sandwich {
		@Override
		public double getPrice() {return 2.5;}
		@Override
		public String[] getIngredients() {return new String[]{"bread", "cheese", "lettuce", "carrots", "tomatoes"};}
	}

	public static class CheeseMayoVegetableSandwich implements Sandwich {
		@Override
		public double getPrice() {return 3;}
		@Override
		public String[] getIngredients() {return new String[]{"bread", "cheese", "mayonnaise", "lettuce", "carrots", "tomatoes"};}
	}

	public static class HamSandwich implements Sandwich {
		@Override
		public double getPrice() {return 2;}
		@Override
		public String[] getIngredients() {return new String[]{"bread", "ham"};}
	}

	public static class HamMayoSandwich implements Sandwich {
		@Override
		public double getPrice() {return 2.5;}
		@Override
		public String[] getIngredients() {return new String[]{"bread", "ham", "mayonnaise"};}
	}

	public static class HamVegetableSandwich implements Sandwich {
		@Override
		public double getPrice() {return 2.5;}
		@Override
		public String[] getIngredients() {return new String[]{"bread", "ham", "lettuce", "carrots", "tomatoes"};}
	}

	public static class HamMayoVegetableSandwich implements Sandwich {
		@Override
		public double getPrice() {return 3;}
		@Override
		public String[] getIngredients() {return new String[]{"bread", "ham", "mayonnaise", "lettuce", "carrots", "tomatoes"};}
	}

	public static void main(String[] args) {
		String[] order = {"cheese", "cheese with mayo", "ham with vegetables"};
		double total = 0;

		for (int i = 0; i < order.length; i++) {
			String item = order[i];
			Sandwich s = null;
			switch(item) {
			case "cheese": s = new CheeseSandwich(); break;
			case "cheese with mayo": s = new CheeseMayoSandwich(); break;
			case "cheese with vegetables": s = new CheeseVegetableSandwich(); break;
			case "cheese with mayo and vegetables": s = new CheeseMayoVegetableSandwich(); break;
			case "ham": s = new HamSandwich(); break;
			case "ham with mayo": s = new HamMayoSandwich(); break;
			case "ham with vegetables": s = new HamVegetableSandwich(); break;
			case "ham with mayo and vegetables": s = new HamMayoVegetableSandwich(); break;
			}
			total += s.getPrice();
		}

		System.out.println("Total price of order: " + total);
	}
}