Java cloning abstract objects

Question

I\'m wondering if there is any way to do the following. I have an abstract class, Shape, and all its different subclasses and I want to override the clone metho

Answer 1

Although I doubt it is a good idea, you could use reflection:

import java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;

public class Test {

    public static void main(String[] args) {        
        Square s1 = new Square("test");
        Square s2 = (Square) s1.clone();

        // show that s2 contains the same data  
        System.out.println(s2);
        // show that s1 and s2 are really different objects
        System.out.println(s1 == s2);
    }

    public static abstract class Shape {
        private String str;

        public Shape(String str) {
            this.str = str;
        }

        public Shape clone() {          
            try {
                Class cl = this.getClass();
                Constructor cons = cl.getConstructor(String.class);
                return (Shape) cons.newInstance(this.toString());           
            } catch (NoSuchMethodException | SecurityException |
                     InstantiationException | IllegalAccessException |
                     IllegalArgumentException | InvocationTargetException e) {  
                e.printStackTrace();
            }           

            return null;
        }

        @Override
        public String toString() {
            return str;
        }
    }

    public static class Square extends Shape {
        public Square(String str) {
            super(str);
        }
    }   
}