this关键字在继承中的使用

public class ChildA extends Father {
    void add() {
        System.out.println("A中的ADD");
    }
}

public class ChildB extends Father {
    void add() {
        System.out.println("B中的ADD");
    }
}

import org.apache.catalina.filters.AddDefaultCharsetFilter;

public class Father {
    public Father() {
        System.out.println(this);
    }
    void add() {
        System.out.println("父类中的ADD");
    }
    
}

public class Main {
    public static void main(String[] args) {
        Father a = new ChildA();
        a.add();
    }
}