update:demo4

com/study/demo4/TestTransport.java

@@ -0,0 +1,22 @@
+package com.study.demo4;
+
+public class TestTransport {
+  public static void main(String[] args) {
+    // 测试自行车配送
+    DeliveryFeeCalculator bike = new BikeDeliveryCalculator();
+    System.out.println("自行车配送 3km: ¥" + bike.calculateFee(3));
+    System.out.println("自行车配送 8km: ¥" + bike.calculateFee(8));
+
+    // 测试汽车配送
+    DeliveryFeeCalculator car = new CarDeliveryCalculator();
+    System.out.println("汽车配送 3km: ¥" + car.calculateFee(3));
+    System.out.println("汽车配送 8km: ¥" + car.calculateFee(8));
+
+    // 对比不同距离的费用
+    System.out.println("\n费用对比:");
+    for (int km = 1; km <= 10; km++) {
+      System.out.printf("%dkm: 自行车¥%.1f, 汽车¥%.1f%n",
+          km, bike.calculateFee(km), car.calculateFee(km));
+    }
+  }
+}