Builder Pattern

title: Builder Design Pattern description: Complex objects step-by-step banana

Complex object ko step-by-step construct karna.

Implementation

java exampleWoHoTech

class Pizza {
    private String size;
    private String crust;
    private List<String> toppings;
    private boolean extraCheese;

    private Pizza(Builder builder) {
        this.size = builder.size;
        this.crust = builder.crust;
        this.toppings = builder.toppings;
        this.extraCheese = builder.extraCheese;
    }

    @Override
    public String toString() {
        return size + " pizza, " + crust + " crust, toppings: " + toppings + (extraCheese ? " + extra cheese" : "");
    }

    // Static Builder class
    public static class Builder {
        private String size;
        private String crust = "thin"; // default
        private List<String> toppings = new ArrayList<>();
        private boolean extraCheese = false;

        public Builder(String size) { this.size = size; }
        public Builder crust(String crust) { this.crust = crust; return this; }
        public Builder topping(String topping) { this.toppings.add(topping); return this; }
        public Builder extraCheese() { this.extraCheese = true; return this; }
        public Pizza build() { return new Pizza(this); }
    }
}

// Use — Method chaining
Pizza pizza = new Pizza.Builder("Large")
    .crust("thick")
    .topping("mushrooms")
    .topping("olives")
    .extraCheese()
    .build();

System.out.println(pizza);

Lombok @Builder

java exampleWoHoTech

@Builder
@Data
public class User {
    private String name;
    private String email;
    private int age;
}

User user = User.builder().name("Ram").email("ram@mail.com").age(25).build();

Use Cases

StringBuilder
Lombok @Builder
Complex configuration objects
Test data builders

title: Builder Design Pattern description: Complex objects step-by-step banana

Complex object ko step-by-step construct karna.

Implementation

java exampleWoHoTech

class Pizza {
    private String size;
    private String crust;
    private List<String> toppings;
    private boolean extraCheese;

    private Pizza(Builder builder) {
        this.size = builder.size;
        this.crust = builder.crust;
        this.toppings = builder.toppings;
        this.extraCheese = builder.extraCheese;
    }

    @Override
    public String toString() {
        return size + " pizza, " + crust + " crust, toppings: " + toppings + (extraCheese ? " + extra cheese" : "");
    }

    // Static Builder class
    public static class Builder {
        private String size;
        private String crust = "thin"; // default
        private List<String> toppings = new ArrayList<>();
        private boolean extraCheese = false;

        public Builder(String size) { this.size = size; }
        public Builder crust(String crust) { this.crust = crust; return this; }
        public Builder topping(String topping) { this.toppings.add(topping); return this; }
        public Builder extraCheese() { this.extraCheese = true; return this; }
        public Pizza build() { return new Pizza(this); }
    }
}

// Use — Method chaining
Pizza pizza = new Pizza.Builder("Large")
    .crust("thick")
    .topping("mushrooms")
    .topping("olives")
    .extraCheese()
    .build();

System.out.println(pizza);

Lombok @Builder

java exampleWoHoTech

@Builder
@Data
public class User {
    private String name;
    private String email;
    private int age;
}

User user = User.builder().name("Ram").email("ram@mail.com").age(25).build();

Use Cases

StringBuilder
Lombok @Builder
Complex configuration objects
Test data builders

Builder Pattern

Implementation

Lombok @Builder

Use Cases

Continue learning this concept

Builder Pattern

Implementation

Lombok @Builder

Use Cases

Continue learning this concept