Clone

(a)

public class CloneFirst implements Cloneable{
   
    int a;
    String b;
    //As you can see from the Oracle Spec the following lines are written
    public CloneFirst cloneMethod() throws CloneNotSupportedException{
       
        /*
         * %W% %E%
         *
         * Copyright (c) 2006, Oracle and/or its affiliates. All rights reserved.
         * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
        */       
        /**
         * Creates and returns a copy of this object.  The precise meaning
         * of "copy" may depend on the class of the object. The general
         * intent is that, for any object <tt>x</tt>, the expression:
         * <blockquote>
         * <pre>
         * x.clone() != x</pre></blockquote>
         * will be true, and that the expression:
         * <blockquote>
         * <pre>
         * x.clone().getClass() == x.getClass()</pre></blockquote>
         * will be <tt>true</tt>, but these are not absolute requirements.
         * While it is typically the case that:
         * <blockquote>
         * <pre>
         * x.clone().equals(x)</pre></blockquote>
         * will be <tt>true</tt>, this is not an absolute requirement.
         * <p>
         * By convention, the returned object should be obtained by calling
         * <tt>super.clone</tt>.  If a class and all of its superclasses (except
         * <tt>Object</tt>) obey this convention, it will be the case that
         * <tt>x.clone().getClass() == x.getClass()</tt>.
         * <p>
         * By convention, the object returned by this method should be independent
         * of this object (which is being cloned).  To achieve this independence,
         * it may be necessary to modify one or more fields of the object returned
         * by <tt>super.clone</tt> before returning it.  Typically, this means
         * copying any mutable objects that comprise the internal "deep structure"
         * of the object being cloned and replacing the references to these
         * objects with references to the copies.  If a class contains only
         * primitive fields or references to immutable objects, then it is usually
         * the case that no fields in the object returned by <tt>super.clone</tt>
         * need to be modified.
         * <p>
         * The method <tt>clone</tt> for class <tt>Object</tt> performs a
         * specific cloning operation. First, if the class of this object does
         * not implement the interface <tt>Cloneable</tt>, then a
         * <tt>CloneNotSupportedException</tt> is thrown. Note that all arrays
         * are considered to implement the interface <tt>Cloneable</tt>.
         * Otherwise, this method creates a new instance of the class of this
         * object and initializes all its fields with exactly the contents of
         * the corresponding fields of this object, as if by assignment; the
         * contents of the fields are not themselves cloned. Thus, this method
         * performs a "shallow copy" of this object, not a "deep copy" operation.
         * <p>
         * The class <tt>Object</tt> does not itself implement the interface
         * <tt>Cloneable</tt>, so calling the <tt>clone</tt> method on an object
         * whose class is <tt>Object</tt> will result in throwing an
         * exception at run time.
         *
         * @return     a clone of this instance.
         * @exception  CloneNotSupportedException  if the object's class does not
         *               support the <code>Cloneable</code> interface. Subclasses
         *               that override the <code>clone</code> method can also
         *               throw this exception to indicate that an instance cannot
         *               be cloned.
         * @see java.lang.Cloneable
         */
        return (CloneFirst)super.clone();
       
    }
}

(b)

public class CloneCallingFirst extends CloneFirst{

    public static void main(String[] args) throws CloneNotSupportedException {
      
        CloneFirst cf1 = new CloneFirst();
        cf1.a=10;
        cf1.b="Ten";
        CloneFirst cf2;
        cf2 = cf1.cloneMethod();
      
        System.out.println("The Answer for a is " + cf2.a);
        System.out.println("The Answer for b is " + cf2.b);
      
    }

}