上传文件至 'w3'

w3/w3car

@@ -0,0 +1,78 @@
+package com.rental;
+
+public class Car {
+    private final String licensePlate;
+    private String brand;
+    private String model;
+    private double dailyRent;
+    private boolean isRented;
+    private static int totalCars = 0;
+
+    // 全参构造
+    public Car(String licensePlate, String brand, String model, double dailyRent) {
+        this.licensePlate = licensePlate;
+        this.brand = brand;
+        this.model = model;
+        this.dailyRent = dailyRent;
+        this.isRented = false;
+        totalCars++;
+    }
+
+    // 重载构造（默认日租金300）
+    public Car(String licensePlate, String brand, String model) {
+        this(licensePlate, brand, model, 300.0);
+    }
+
+    // Getter/Setter
+    public String getLicensePlate() { return licensePlate; }
+    public String getBrand() { return brand; }
+    public void setBrand(String brand) { this.brand = brand; }
+    public String getModel() { return model; }
+    public void setModel(String model) { this.model = model; }
+    public double getDailyRent() { return dailyRent; }
+
+    public void setDailyRent(double dailyRent) {
+        if (dailyRent > 0) {
+            this.dailyRent = dailyRent;
+        } else {
+            System.out.println("日租金必须大于0，修改失败！");
+        }
+    }
+
+    public boolean isRented() { return isRented; }
+
+    // 业务方法
+    public void rentCar() {
+        if (isRented) {
+            System.out.println("车辆已租出，无法再次租用");
+        } else {
+            isRented = true;
+            System.out.println("车辆已成功租出");
+        }
+    }
+
+    public void returnCar() {
+        if (!isRented) {
+            System.out.println("车辆未被租用，无需归还");
+        } else {
+            isRented = false;
+            System.out.println("车辆已成功归还");
+        }
+    }
+
+    public double calculateRent(int days) {
+        return dailyRent * days;
+    }
+
+    public void displayInfo() {
+        System.out.println("车牌号：" + licensePlate +
+                "，品牌：" + brand +
+                "，型号：" + model +
+                "，日租金：" + dailyRent +
+                "元/天，状态：" + (isRented ? "已租出" : "可租"));
+    }
+
+    public static int getTotalCars() {
+        return totalCars;
+    }
+}

w3/w3testcar

@@ -0,0 +1,31 @@
+package com.rental;
+
+public class TestCar {
+    public static void main(String[] args) {
+        Car car1 = new Car("豫A12345", "比亚迪", "汉EV", 280.0);
+        Car car2 = new Car("豫B67890", "特斯拉", "Model 3");
+        Car car3 = new Car("豫C54321", "丰田", "凯美瑞", 220.0);
+
+        System.out.println("=== 初始车辆信息 ===");
+        car1.displayInfo();
+        car2.displayInfo();
+        car3.displayInfo();
+
+        System.out.println("\n=== 测试租车/还车 ===");
+        car1.rentCar();
+        car1.rentCar();
+        car1.returnCar();
+        car1.returnCar();
+
+        System.out.println("\n=== 计算5天租金 ===");
+        double rent = car2.calculateRent(5);
+        System.out.println("车辆" + car2.getLicensePlate() + "租赁5天总租金：" + rent + "元");
+
+        System.out.println("\n=== 测试非法日租金修改 ===");
+        car3.setDailyRent(-100);
+        System.out.println("修改后日租金：" + car3.getDailyRent() + "元/天（保持原值）");
+
+        System.out.println("\n=== 总车辆数 ===");
+        System.out.println("当前系统中车辆总数：" + Car.getTotalCars() + "辆");
+    }
+}