Programozás. Java. Mi a a hiba?

Ezt írja ki:

Note: Vectordemo.java uses unchecked or unsafe operations.

Note: Recompile with -Xlint:unchecked for details.

A kód:

import java.util.*;

class Vectordemo{

public static void main(String[] args){

Vector v = new Vector(3,2);

System.out.println("Initial size (kezdeti ertek): " + v.size());

System.out.println("Initial capacity: " + v.capacity());

v.addElement(new Integer(1));

v.addElement(new Integer(2));

v.addElement(new Integer(3));

v.addElement(new Integer(4));

System.out.println("Capacity after four additions: " + v.capacity());

v.addElement(new Double(5.45));

System.out.println("Current capacity: " + v.capacity());

System.out.println("First element: " + (Integer)v.firstElement());

System.out.println("Last element: " + (Integer)v.lastElement());

if(v.contains(new Integer(3))){

System.out.println("Vector conatins 3.");

}

Enumeration vEnum = v.elements();

System.out.println("\\nElements in vector: ");

while(vEnum.hasMoreElements()){

System.out.println(vEnum.nextElement() + " ");

System.out.println();

}

}

}