Java/com/study/demo13/OrderService.java

package com.study.demo13;

abstract class Order {
    protected double amount;

    public Order(double amount) {
        this.amount = amount;
    }

    abstract double calculatePrice();
    abstract String getOrderType();
}

class NormalOrder extends Order {
    public NormalOrder(double amount) {
        super(amount);
    }

    @Override
    double calculatePrice() {
        return amount;
    }

    @Override
    String getOrderType() {
        return "NORMAL";
    }
}

class DiscountOrder extends Order {
    public DiscountOrder(double amount) {
        super(amount);
    }

    @Override
    double calculatePrice() {
        return amount * 0.8;
    }

    @Override
    String getOrderType() {
        return "DISCOUNT";
    }
}

public class OrderService {
    public static void main(String[] args) {
        Order normal = new NormalOrder(100.0);
        Order discount = new DiscountOrder(100.0);
        Order normal2 = new NormalOrder(250.5);
        Order discount2 = new DiscountOrder(300.0);

        System.out.println("Order Type: " + normal.getOrderType() + ", Final Price: " + normal.calculatePrice());
        System.out.println("Order Type: " + discount.getOrderType() + ", Final Price: " + discount.calculatePrice());
        System.out.println("Order Type: " + normal2.getOrderType() + ", Final Price: " + normal2.calculatePrice());
        System.out.println("Order Type: " + discount2.getOrderType() + ", Final Price: " + discount2.calculatePrice());
    }
}