How do I implement the Composite Pattern in Java?

How do I implement the Composite Pattern in Java?

The Composite Pattern allows you to compose objects into tree structures to represent part-whole hierarchies. Would you like a code example?

Yes, please provide a code example.

Sure! Here's a simple example:

import java.util.ArrayList;
import java.util.List;

// Component
interface Graphic {
    void draw();
}

// Leaf
class Circle implements Graphic {
    public void draw() {
        System.out.println("Drawing a Circle");
    }
}

// Leaf
class Square implements Graphic {
    public void draw() {
        System.out.println("Drawing a Square");
    }
}

// Composite
class CompositeGraphic implements Graphic {
    private List<Graphic> graphics = new ArrayList<>();

    public void add(Graphic graphic) {
        graphics.add(graphic);
    }

    public void draw() {
        for (Graphic graphic : graphics) {
            graphic.draw();
        }
    }
}

// Client
public class Main {
    public static void main(String[] args) {
        CompositeGraphic graphic = new CompositeGraphic();
        graphic.add(new Circle());
        graphic.add(new Square());
        graphic.draw();
    }
}

This code demonstrates how to create a composite structure with circles and squares.

What are the benefits of using the Composite Pattern?

The Composite Pattern simplifies client code by treating individual objects and compositions uniformly. It also promotes flexibility in adding new components.