package extra;

import java.util.ArrayList;

import java.util.List;

class MyArrayList<E> extends ArrayList<E> {

@Override

public boolean add(E e) {

if (e instanceof Integer || e instanceof Float || e instanceof Double) {

super.add(e);

return true;

} else {

throw new ClassCastException("Only Integer, Float, and Double are supported.");

}

}

}

public class ArrayListNumbers {

public static void main(String[] args) {

List<Object> list = new MyArrayList<>();

try {

list.add(15);

list.add(1.2F);

list.add(3.1415D);

} catch (Exception e) {

e.printStackTrace();

}

System.out.println(list);

}

}