关于克隆的一些疑问，求大大指教！该如何解决

package c12;import java.util.*; class Int {    private int i;    public Int(int ii) { i = ii; }    public void increment() { i++; }    public String toString() {        return Integer.toString(i);    } } public class Cloning {    public static void main(String[] args) {        Vector v = new Vector();        for(int i = 0; i < 10; i++ )           v.addElement(new Int(i));        System.out.println("v: " + v);        Vector v2 = (Vector)v.clone();       //Increment all v2's elements:       for(Enumeration e = v2.elements();             e.hasMoreElements(); )           ((Int)e.nextElement()).increment();         //See if it changed v's elements:        System.out.println("v2:"+v2);       System.out.println("v:"+v);      if (v2!=v)          System.out.println("This is different");      // System.out.println("v: " + v);    } }