update:demo13

com/study/demo13/OrderService.java

@@ -0,0 +1,58 @@
+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());
+    }
+}