Builder Pattern in Java: Explanation & Practice

Problem summary

Create a Pizza class with a Builder that allows setting size, cheese, pepperoni, and mushrooms.

Starter code

class Pizza {
    // Fields: size, cheese, pepperoni, mushrooms
    // Private constructor
    // Builder inner class
}

public class Main {
    public static void main(String[] args) {
        Pizza pizza = new Pizza.Builder("Large")
            .cheese(true)
            .pepperoni(true)
            .mushrooms(false)
            .build();
        
        System.out.println(pizza);
        // Output: Pizza: Large, Cheese: true, Pepperoni: true, Mushrooms: false
    }
}

Expected output and test cases

• Builder constructs pizza correctly

  Pizza: Large, Cheese: true, Pepperoni: true, Mushrooms: false

Hints

1. Builder class with same fields
2. Each setter returns Builder for chaining
3. build() returns new Pizza with Builder's values

Related OOP Basics exercises

• Practice Singleton Pattern in Java
• Practice Factory Pattern in Java
• Practice Observer Pattern in Java

Practice all OOP Basics exercises · Run this idea in the Java compiler