public class SwapTester
{
    public static void swap3(Integer x, Integer y)
    {
        int t = x.intValue();
        x.setInt(y.intValue());
        y.setInt(t);
    }
    public static void swap2(Integer x, Integer y)
    {
        Integer t = x;
        x = y;
        y = t;
    }
    public static void swap(int x, int y)
    {
        System.out.println( "before" + x + ", " + y);
        int t = x;
        x = y;
        y = t;
        System.out.println( "after" + x + ", " + y);
    }

    public static void main(String[] args)
    {
        Integer ia = 1;
        Integer ib = 2;
        System.out.println( ia + ", " + ib);
        swap(ia, ib);
        System.out.println( ia + ", " + ib);

  //     int a = 1;
  //     int b = 2;
  //     System.out.println( a + ", " + b);
  //     swap(a, b);
  //     System.out.println( a + ", " + b);
         
    }
     
}