JAVA重写与多态

 父类：

package cn.bdqn.demo01;
 
public class Pet {
 
		private String name;
		private int health;
		private int love;
		
		public Pet() {
			super();
		}
		
		public Pet(String name, int health, int love) {
			super();
			this.name = name;
			this.health = health;
			this.love = love;
		}
		
		
		
		public String getName() {
			return name;
		}
		public void setName(String name) {
			this.name = name;
		}
		public int getHealth() {
			return health;
		}
		public void setHealth(int health) {
			this.health = health;
		}
		public int getLove() {
			return love;
		}
		public void setLove(int love) {
			this.love = love;
		}
		
		
		
		@Override
		public String toString() {
			return "宠物信息：name=" + name + ", health=" + health + ", love=" + love;
		}
		
		
		//定义一个去医院看病的方法
		public void toHospital(){
			System.out.println("宠物生病了，带宠物去医院看病.............");
		}
		
}

Master类：

package cn.bdqn.demo01;
 
public class Master {
 
		//定义给Pet类对象看病的方法
	public void cure(Pet pet){
		//传递过来的pet的健康值<60{
		System.out.println("宠物生病了，需要去医院看病");
		pet.toHospital();
	}
}

Cat类

package cn.bdqn.demo01;
 
public class Cat extends Pet{
	
	//定义属性
	private String color;
 
	
	public Cat() {
		super();
	}
 
 
	public Cat(String name, int health, int love, String color) {
		super(name, health, love);
		this.color = color;
	}
 
 
	public String getColor() {
		return color;
	}
 
 
	public void setColor(String color) {
		this.color = color;
	}
 
 
	
 
	
 
 
	@Override
	public String toString() {
		return "宠物信息：name=" + this.getName() + ", health=" + this.getHealth()
				+ ", love=" + this.getLove() + ",color=" + color;
	}
 
 
	//pet类中toHospital（）不足以满足cat类对象看病的需求，所以需要重写
	@Override
	public void toHospital() {
			if(this.getHealth()<60){
				System.out.println("打针，吃药.....");
				this.setHealth(80);
			}
	}
}

 Dog类：

package cn.bdqn.demo01;
 
public class Dog extends Pet {
 
		private String strain;
 
		public Dog() {
			super();
		}
 
		public Dog(String name, int health, int love, String strain) {
			super(name, health, love);
			this.strain = strain;
		}
 
		public String getStrain() {
			return strain;
		}
 
		public void setStrain(String strain) {
			this.strain = strain;
		}
 
		@Override
		public String toString() {
			return "宠物信息：name=" + this.getName() + ", health=" + this.getHealth() + ", love=" + this.getLove() + "，strain="+strain;
		}
 
		@Override
		public void toHospital() {
			if(this.getHealth()<60){
				System.out.println("打针.......");
				this.setHealth(90);
			}
		}
	
		
}

测试：

package cn.bdqn.demo01;
 
public class Test {
 
	public static void main(String[] args) {
			//创建Master类对象，带宠物去看病
		Master master = new Master();
		
		//创建Cat类对象
		Cat cat1 = new Cat("Tom",55,99,"白色");
		System.out.println(cat1.getHealth());
		
		master.cure(cat1);//方法调用的时候，需要什么给什么
		
		System.out.println(cat1.getHealth());
		System.out.println("------------------------");
		
		Dog dog1 = new Dog("可乐",45,88,"柯基");
		System.out.println(dog1.getHealth());
		master.cure(dog1);
		System.out.println(dog1.getHealth());
		System.out.println("-------------------------");
		
		Penguin p1 = new Penguin("QQ",12,99,"公");
		System.out.println(p1.getHealth());
		master.cure(p1);
		System.out.println(p1.getHealth());
	
		System.out.println("-------------------");
		
		
		//类名 对象名 = new 子类类名（）；
		//向上转型： 父类的引用指向子类的实例
		Pet pet1 = new Cat("黑猫警长",45,100,"黑色");
		master.cure(pet1);
		System.out.println("------------------------");
		
		pet1 = new Dog("旺财",40,99,"哈士奇");
		master.cure(pet1);
	}
 
}