java多态-猫狗宠物店案例

猫类（子类）

public class Cat extends Pet{
	private String gender;
	
	public String getgender() {
		return gender;
	}
	public void setgender(String gender) {
		this.gender = gender;
	}
	@Override
	public void showInfo() {
		System.out.println("名：" + super.getName());
		System.out.println("健康值：" + super.getHealth());
		System.out.println("亲密度：" + super.getLove());
		System.out.println("性别：" + gender);
	}
	public Cat() {
		super();
	}
	public Cat(String gender, String name, int health, int love) {
		super(name, health, love);
		this.setgender(gender);
	}
	
}

 狗类（子类）

public class Dog extends Pet{
	private String breed;
	
	public String getBreed() {
		return breed;
	}
	public void setBreed(String breed) {
		this.breed = breed;
	}

	public Dog() {
		super();
	}
	public Dog(String name, int health, int love, String breed) {
		super(name, health, love);
		this.breed = breed;
	}
	
	@Override
	public void showInfo() {
		super.showInfo();
		System.out.println("品种：" + breed);
	}
	public Dog(String name, int health, int love) {
		this(name, health, love, null);
	}
}

宠物类（父类）

public class Pet {
	private String name;
	private int health;
	private int love;
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getHealth() {
		return health;
	}
	public void setHealth(int health) {
		if (health < 0 || health > 100) {
			System.out.println("您输入有误！已设置为默认值！");
			health = 60;
		}
		this.health = health;
	}
	public int getLove() {
		return love;
	}
	public void setLove(int love) {
		if (love < 0 || love > 100) {
			System.out.println("您输入有误！已设置为默认值！");
			love = 60;
		}
		this.love = love;
	}
	
	public void showInfo() {
		System.out.println("名：" + name);
		System.out.println("健康值：" + health);
		System.out.println("亲密度：" + love);
	}
	public Pet() {
		super();
	}
	public Pet(String name, int health, int love) {
		super();
		this.setHealth(health);
		this.setName(name);
		this.setLove(love);
	}
	
}

测试类

public class Demo02 {

	private static Pet[] petArr = new Pet[4];
	
	static {
		petArr[0] = new Dog("小花", 88, 88, "柴犬");
		petArr[1] = new Dog("大花", 88, 77, "拉布拉多");
		petArr[2] = new Cat("公", "小猫", 77, 77);
		petArr[3] = new Cat("母", "大猫", 77, 66);
	}
	
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		System.out.println("欢迎来到宠物店");
		String breed = null;
		String gender = null;
		while (true) {
			System.out.println("请选择：1.狗2.猫");
			String choice = input.next();
			switch (choice) {
			case "1":
				System.out.println("请输入狗的品种：1.柴犬2.拉布拉多");
				breed = input.nextInt() == 1 ? "柴犬" : "拉布拉多";
				break;
			case "2":
				System.out.println("请输入猫的性别：1.公2.母");
				gender = input.nextInt() == 1 ? "公" : "母";
				break;
			default:	
				System.out.println("输入错误！");
				break;
			}
			break;
		}
		
		Demo02 demo02 = new Demo02();
		Pet pet = demo02.getPet(breed, gender);
		if (pet != null) {
			pet.showInfo();
			return;
		}
		System.out.println("对不起！没有您找的宠物！");
	}
	
    // 得到宠物（满足条件的话返回这个宠物）
	public Pet getPet(String breed, String gender) {
		for (Pet pet : petArr) {
			if (pet instanceof Dog) {
				Dog dog = (Dog)pet;
				if (dog.getBreed().equals(breed)) {
					return dog;
				}
			} else if (pet instanceof Cat) {
				Cat cat = (Cat)pet;
				if (cat.getgender().equals(gender)) {
					return cat;
				}
			} 
		}
		return null;
	}
}