java面向对象之父类的引用指向子类的对象

package Text;

public class Job {
    public void dowork(){
        
    }
}

package Text;

public class Luosidao extends Job{
    public void dowork(){
        System.out.println("螺丝刀拧螺丝。。。");
    }
}

package Text;

public class Chanzi extends Job{

    @Override
    public void dowork() {
        System.out.println("铲子铲土。。。");
    }
    
    public void test(){
        System.out.println("测试方法");
    }
}

package Tool;

import Text.Chanzi;
import Text.Job;
import Text.Luosidao;

public class Tool3 {
    public static void main(String[] args) {
        Job a =new Luosidao();
        Job b =new Chanzi();
        a.dowork();
        b.dowork();
        Chanzi c =(Chanzi)b;//无法调用子类方法，所以强转
        c.test();
    }
}