Question

Imagine you're working for a fast-food restaurant. get details returns name of the burger and getPrice return the price of the meal. Java

Using Decorator pattern make class BurgerToppings:

-Each topping is an extra $1 and the name provided in the constructor

-getTotalPrice: returns total price of burger + toppings

-getDetails: returns the burger name + name of topping with the word (extra)

Output expected:

Ordering BigMac + extra pickles+ extra cheese
Total price = 6.0

public interface Burger{
    double C();
    String getDetails();
}

public class BigMac implements Burger{
    private String order;
    private double price ;

    public BigMac() {
        this.order= "Big Mac";
        this.price = 4.00;
    }

    @Override
    public double getPrice() {
        return price;
    }

    @Override
    public String getorder() {
        return name;
    }
}

Answer 1

JAVA CODE: BurgerTester.java

NOTE: You can put each of the classes and interface in separate java files and then make all of them public, i have used only one java file for simplicity.

package project1;
interface Burger{
   public double getPrice();
   public String getDetails();
}
class BigMac implements Burger{
   private String order;
   private double price;
   public BigMac() {
       this.order="Big Mac";
       this.price=4.00;
   }
   @Override
   public double getPrice() {
       return price;
   }
   @Override
   public String getDetails() {
       return order;
   }
}
abstract class BurgerDecorator implements Burger{
   protected Burger burger;
   public BurgerDecorator(Burger burger) {
       this.burger=burger;
   }
   @Override
   public String getDetails() {
       return burger.getDetails();
   }
   @Override
   public double getPrice() {
       return burger.getPrice();
   }
}
class BurgerToppings extends BurgerDecorator{
   private String toppings[];
   public BurgerToppings(Burger burger, String toppings[]) {
       super(burger);
       this.toppings=toppings;
   }
   @Override
   public double getPrice() {
       return burger.getPrice() + toppings.length;
   }
   @Override
   public String getDetails() {
       StringBuilder sb=new StringBuilder(burger.getDetails());
       for(int i=0;i<toppings.length;i++) {
           sb.append(" + extra "+toppings[i]);
       }
       return sb.toString();
   }
}
public class BurgerTester {
   public static void main(String[] args) {
       BurgerToppings bt=new BurgerToppings(new BigMac(),new String[] {"pickles","cheese"});
       System.out.println("Ordering "+bt.getDetails());
       System.out.println("Total price = "+bt.getPrice());
   }
}

Output: