How can I serialize an interface?

Question

Suppose I have a Serializable class ShapeHolder that owns an object that implements a Serializable Shape interface. I wa

Answer 1

import java.io.*;

public class ExampleSerializableClass implements Serializable {
    private static final long serialVersionUID = 0L;

    transient private Shape shape;
    private String shapeClassName;

    private void writeObject(ObjectOutputStream out) throws IOException {
        shapeClassName = shape.getClass().getCanonicalName();
        out.defaultWriteObject();
    }

    private void readObject(ObjectInputStream in) 
           throws IOException, ClassNotFoundException, 
              InstantiationException, IllegalAccessException {
        in.defaultReadObject();
        Class cls = Class.forName(shapeClassName);
        shape = (Shape) cls.newInstance();
    }
}