java 接口

package net.elaina.interface01;

public abstract class Animal {
    private String name;
    private int age;


    public Animal() {
    }

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

    /**
     * 获取
     * @return name
     */
    public String getName() {
        return name;
    }

    /**
     * 设置
     * @param name
     */
    public void setName(String name) {
        this.name = name;
    }

    /**
     * 获取
     * @return age
     */
    public int getAge() {
        return age;
    }

    /**
     * 设置
     * @param age
     */
    public void setAge(int age) {
        this.age = age;
    }

    public String toString() {
        return "Animal{name = " + name + ", age = " + age + "}";
    }

    public abstract void eat();
}

package net.elaina.interface01;

public interface Swim {
    public abstract void swim();
}

package net.elaina.interface01;

public class Rabbit extends Animal {

    public Rabbit() {
    }

    public Rabbit(String name, int age) {
        super(name, age);
    }

    @Override
    public void eat() {
        System.out.println("兔子在吃胡萝卜");
    }
}

package net.elaina.interface01;

public class Frog extends Animal implements Swim{

    public Frog() {
    }

    public Frog(String name, int age) {
        super(name, age);
    }

    @Override
    public void eat() {
        System.out.println("青蛙在吃虫子");
    }

    @Override
    public void swim() {
        System.out.println("青蛙在蛙泳");
    }
}

package net.elaina.interface01;

public class Dog extends Animal implements Swim{

    public Dog() {
    }

    public Dog(String name, int age) {
        super(name, age);
    }

    @Override
    public void eat() {
        System.out.println("狗吃骨头");
    }

    @Override
    public void swim() {
        System.out.println("狗刨");
    }
}

package net.elaina.interface01;

public class Test {
    public static void main(String[] args) {
        Frog f = new Frog("小青",1);
        System.out.println(f.getName() + ", " + f.getAge());
        f.eat();
        f.swim();

        Rabbit r = new Rabbit("小白",2);
        System.out.println(r.getName() + ", " + r.getAge());
        r.eat();
    }
}

打印：

小青, 1
青蛙在吃虫子
青蛙在蛙泳
小白, 2
兔子在吃胡萝卜