[Java] 纯文本查看 复制代码

package com.day9;
/*
代码中使用多态作为参数但是调用不出子类的特有方法
 */
public class Abstract_Dongwu {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Mao m = new Mao("白猫",8);
		System.out.println("这个是一只：" + m.getName() + "它的年龄是：" + m.getAge());
		m.eat();
		m.sleep();
		
		JumpMao jm = new JumpMao("黑猫",3);
		System.out.println("这个是一只：" + jm.getName() + "它的年龄是：" + jm.getAge());
		jm.eat();
		jm.sleep();
		jm.jump();
		
		Gou g = new Gou("白狗",10);
		System.out.println("这个是一只：" + g.getName() + "它的年龄是：" + g.getAge());
		g.eat();
		g.sleep();
		
		JumpGou jg = new JumpGou("黑狗",5);
		System.out.println("这个是一只：" + jg.getName() + "它的年龄是：" + jg.getAge());
		jg.eat();
		jg.sleep();
		jg.jump();
		
		method(new Mao("张三",23));
		method(new Gou("李四",24));
		//method(new Dongwu("王五",25));       //动物类是抽象类，不能创建对象
		method(new JumpMao("赵六",26));
		method(new JumpGou("刘七",27));
		
		Dongwu d = new JumpMao("ssss",2);
		JumpMao x = (JumpMao) d;
		System.out.println("这个是一只：" + x.getName() + "它的年龄是：" + x.getAge());
		x.jump();
	}
	
	public static void method(Dongwu d) {
		if(d instanceof Mao) {
			Mao m = (Mao) d;
			System.out.println("这个是一只：" + m.getName() + "它的年龄是：" + m.getAge());
			m.eat();
			m.sleep();
		}else if(d instanceof Gou) {
			Gou g = (Gou) d;
			System.out.println("这个是一只：" + g.getName() + "它的年龄是：" + g.getAge());
			g.eat();
			g.sleep();
		}else if(d instanceof JumpMao) {
			JumpMao jm = (JumpMao) d;
			System.out.println("这个是一只：" + jm.getName() + "它的年龄是：" + jm.getAge());
			jm.eat();
			jm.sleep();
			jm.jump();     //为什么这里的方法调用不出来
		}else if(d instanceof JumpGou) {
			JumpGou jg = (JumpGou) d;
			System.out.println("这个是一只：" + jg.getName() + "它的年龄是：" + jg.getAge());
			jg.eat();
			jg.sleep();
			jg.jump();     
		}else {
			System.out.println("动物类的方法是抽象的");
		}
	}

}
/*
案例演示：
	动物类：姓名，年龄，吃饭，睡觉
	猫和狗
	动物培训借口：跳高
*/
abstract class Dongwu {      //抽象类：动物
	private String name;       //名字
	private int age;			//年龄
	public Dongwu() {			//空参
		
	}
	public Dongwu(String name,int age) {    //有参
		this.name = name;
		this.age = age;
	}
	
	public void setName(String name) {   //设置名字
		this.name = name;
	}
	public String getName() {          //获取名字
		return name;
	}
	
	public void setAge(int age) {         //设置年龄
		this.age = age;
	}
	public int getAge() {     //获取年龄
		return age;
	}
	
	public abstract void eat();         //抽象方法吃
	public abstract void sleep();       //抽象方法睡
}

interface Jump {                 //接口跳高
	public abstract void jump();           //抽象方法跳高
}

class Mao extends Dongwu {        //猫类继承动物类
	public Mao() {        //空参
		
	}
	public Mao(String name,int age) {    //有参
		super(name,age);
	}
	
	public void eat() {              //具体化猫类的方法吃
		System.out.println("猫吃鱼");
	}
	public void sleep() {          //具体化猫类的方法睡
		System.out.println("侧着睡");
	}
}

class JumpMao extends Mao implements Jump {    //跳高猫类继承猫类并且实现接口跳高
	public JumpMao() {          //空参
		
	}
	public JumpMao(String name,int age) {     //有参
		super(name,age); 
	}
	
	public void jump() {         //跳高猫类实现接口跳高
		System.out.println("猫跳高");
	}
}

class Gou extends Dongwu {      //狗类继承动物
	public Gou() {      //空参
		 
	}
	public Gou(String name,int age) {      //有参
		super(name,age);
	}
	
	public void eat() {          //具体化狗类的方法吃
		System.out.println("狗吃肉");
	}
	public void sleep() {      //具体化狗类的方法睡
		System.out.println("趴着睡");
	}
}

class JumpGou extends Gou implements Jump {     //跳高狗继承狗类并且实现接口跳高
	public JumpGou() {             //空参
		
	}
	public JumpGou(String name,int age) {     //有参
		super(name,age);
	}
	public void jump() {         //跳高狗类实现接口跳高
		System.out.println("狗跳高");
	}
}

父类不能用子类独有方法是多态的弊端之一，如果一定要用，就得把引用强转成子类的

很不错