定义一个描述动物的抽象类Animal，包含：①实例变量有名字、年龄和雌雄；②一个构造器用来初始化以上变量；③一个抽象的方法voice来描述动物叫声的行为。定义Animal的几种子类，比如Cat、Dog、Tiger，实现方法shout打印：名字+叫声 测试几种子类，调用shout方法

下面是代码实现：

abstract class Animal {
    String name;
    int age;
    boolean isMale;

    public Animal(String name, int age, boolean isMale) {
        this.name = name;
        this.age = age;
        this.isMale = isMale;
    }

    public abstract void voice();
}

class Cat extends Animal {
    public Cat(String name, int age, boolean isMale) {
        super(name, age, isMale);
    }

    @Override
    public void voice() {
        System.out.println(name + " meows");
    }

    public void scratch() {
        System.out.println(name + " scratches");
    }
}

class Dog extends Animal {
    public Dog(String name, int age, boolean isMale) {
        super(name, age, isMale);
    }

    @Override
    public void voice() {
        System.out.println(name + " barks");
    }

    public void wagTail() {
        System.out.println(name + " wags tail");
    }
}

class Tiger extends Animal {
    public Tiger(String name, int age, boolean isMale) {
        super(name, age, isMale);
    }

    @Override
    public void voice() {
        System.out.println(name + " roars");
    }

    public void hunt() {
        System.out.println(name + " hunts");
    }
}

测试代码如下：

public class Main {
    public static void main(String[] args) {
        Cat cat = new Cat("Tom", 3, true);
        Dog dog = new Dog("Snoopy", 5, false);
        Tiger tiger = new Tiger("Tony", 7, true);

        cat.voice();
        dog.voice();
        tiger.voice();
    }
}

输出：

Tom meows
Snoopy barks
Tony roars