重写子类中的抽象方法

abstract class Animal {
    // 抽象方法
    public abstract void makeSound();

    // 具体方法
    public void eat() {
        System.out.println("This animal is eating.");
    }
}

// 子类 Dog
class Dog extends Animal {
    // 重写抽象方法
    @Override
    public void makeSound() {
        System.out.println("Woof!");
    }
}

// 子类 Cat
class Cat extends Animal {
    // 重写抽象方法
    @Override
    public void makeSound() {
        System.out.println("Meow!");
    }
}

public class Main {
    public static void main(String[] args) {
        Animal dog = new Dog();
        dog.makeSound(); // 输出: Woof!
        dog.eat();       // 输出: This animal is eating.

        Animal cat = new Cat();
        cat.makeSound(); // 输出: Meow!
        cat.eat();       // 输出: This animal is eating.
    }
}