JAVA 抽象类

http://docs.oracle.com/javase/tutorial/java/IandI/abstract.html

package peoplePack;

public class JavaApp {
    public static void main(String[] args) {
        Young y = new Young();
        y.action();
    }
}

abstract class People {
    abstract void action();
    public void eat(){
        System.out.println("People eats");
    }
}

class Young extends People{
    public void action(){
        System.out.println("Young Runs");
    }
    
    public void eat(){
        System.out.println("Young eats");
    }
}