//জাভা (Java) – Multi level inheritance
class Chain {
    protected int links;
    public Chain(int links) {
        this.links = links;
    }
    protected void showChain() {
        System.out.println(“1. Chain – has ” + links + ” links”);
    }
}
// A paddle is-a Chain (is-a relation)
class Paddle extends Chain {
    private String size;
    public Paddle(String size, int links) {
        super(links);
        this.size = size;
    }
    protected void showPaddle() {
        System.out.println(“2. Paddle – ” + size + ” with ” + getLinks() + ” links”);
    }
    protected String getSize() {
        return size;
    }
    protected int getLinks() {
        return super.links; // super keyword to access the field of the Chain
    }
}
// A tire is-a Paddle (is-a relation)
class Tire extends Paddle {
    private double diameter;
    public Tire(double diameter, String size, int links) {
        super(size, links);
        this.diameter = diameter;
    }
    protected void showTire() {
        System.out.println(“3. Tire – ” + diameter + ” diameter tire, ” + getSize() + ” paddle with ” + getLinks() + ” links”);
    }
}
// A handle is-a Tire (is-a relation)
class Handle extends Tire {
    private double length;
    private String color;
    public Handle(double length, String color) {
        super(30, “large”, 100);
        this.length = length;
        this.color = color;
    }
    protected void showHandle() {
        System.out.println(“4. Handle – ” + length + ” length and ” + color + ” handle”);
    }
}
// A seat is-a Handle (is-a relation)
class Seat extends Handle {
    private String shape;
    public Seat(String shape) {
        super(20, “red”);
        this.shape = shape;
    }
    protected void showSeat() {
        System.out.println(“5. Seat – ” + shape + ” shape seat”);
    }
}
// A body is-a Seat (is-a relation)
class Body extends Seat {
    private String material;
    public Body(String material) {
        super(“round”);
        this.material = material;
    }
    protected void showBody() {
        System.out.println(“6. Body – ” + material + ” material body”);
    }
}
// A bike is-a Body (is-a relation)
class Bike extends Body {
    public Bike(String material) {
        super(material);
    }
    public void showBike() {
        System.out.println(“The bike has the following features:”);
        showChain();
        showPaddle();
        showTire();
        showHandle();
        showSeat();
        showBody();
    }
}
public class BikeApp {
    public static void main(String[] args) {
        Bike bike = new Bike(“metal”);
        // Displaying the bike details
        bike.showBike();
    }
}

//জাভা (Java) – Output
The bike has the following features:
1. Chain – has 100 links
2. Paddle – large with 100 links
3. Tire – 30.0 diameter tire, large paddle with 100 links
4. Handle – 20.0 length and red handle
5. Seat – round shape seat
6. Body – metal material body

//জাভা (Java) – Multi-level inheritance – Solution with interface
interface Chainable {
    public void showChain();
}
interface Paddable {
    public void showPaddle();
}
interface Tireable {
    public void showTire();
}
interface Handleable {
    public void showHandle();
}
interface Seatable {
    public void showSeat();
}
interface Bodyable {
    public void showBody();
}
class Chain implements Chainable {
    public int links;
    public Chain(int links) {
        this.links = links;
    }
    @Override
    public void showChain() {
        System.out.println(“1. Chain – has ” + links + ” links”);
    }
}
class Paddle implements Paddable {
    private String size;
    public Paddle(String size) {
        this.size = size;
    }
    @Override
    public void showPaddle() {
        System.out.println(“2. Paddle – ” + size);
    }
    public String getSize() {
        return size;
    }
}
class Tire implements Tireable {
    private double diameter;
    public Tire(double diameter) {
        this.diameter = diameter;
    }
    @Override
    public void showTire() {
        System.out.println(“3. Tire – ” + diameter + ” diameter tire”);
    }
}
class Handle implements Handleable {
    private double length;
    private String color;
    public Handle(double length, String color) {
        this.length = length;
        this.color = color;
    }
    @Override
    public void showHandle() {
        System.out.println(“4. Handle – ” + length + ” length and ” + color + ” handle”);
    }
}
class Seat implements Seatable {
    private String shape;
    public Seat(String shape) {
        this.shape = shape;
    }
    @Override
    public void showSeat() {
        System.out.println(“5. Seat – ” + shape + ” shape seat”);
    }
}
class Body implements Bodyable {
    private String material;
    public Body(String material) {
        this.material = material;
    }
    @Override
    public void showBody() {
        System.out.println(“6. Body – ” + material + ” material body”);
    }
}
class Bike implements Chainable, Paddable, Tireable, Handleable, Seatable, Bodyable {
    private Chainable chain; // has-a relation
    private Paddable paddle; // has-a relation
    private Tireable tire; // has-a relation
    private Handleable handle; // has-a relation
    private Seatable seat; // has-a relation
    private Bodyable body; // has-a relation
    // Keeping the constructor for the bike as requested by the user
    public Bike(Chainable chain, Paddable paddle, Tireable tire, Handleable handle, Seatable seat, Bodyable body) {
        this.chain = chain;
        this.paddle = paddle;
        this.tire = tire;
        this.handle = handle;
        this.seat = seat;
        this.body = body;
    }
    public void showBike() {
        System.out.println(“The bike has the following features:”);
        showChain();
        showPaddle();
        showTire();
        showHandle();
        showSeat();
        showBody();
    }
    // Implementing the methods of the interfaces by delegating to the corresponding objects
    @Override
    public void showChain() {
        chain.showChain();
    }
    @Override
    public void showPaddle() {
        paddle.showPaddle();
    }
    @Override
    public void showTire() {
        tire.showTire();
    }
    @Override
    public void showHandle() {
        handle.showHandle();
    }
    @Override
    public void showSeat() {
        seat.showSeat();
    }
    @Override
    public void showBody() {
        body.showBody();
    }
}
public class BikeApp {
    public static void main(String[] args) {
        Chain chain = new Chain(100);
        Paddle paddle = new Paddle(“large”);
        Tire tire = new Tire(30);
        Handle handle = new Handle(20, “red”);
        Seat seat = new Seat(“round”);
        Body body = new Body(“metal”);
        Bike bike = new Bike(chain, paddle, tire, handle, seat, body);
        bike.showBike();
    }
}

//জাভা (Java) – Output
The bike has the following features:
1. Chain – has 100 links
2. Paddle – large
3. Tire – 30.0 diameter tire
4. Handle – 20.0 length and red handle
5. Seat – round shape seat
6. Body – metal material body