Java transfer options

I know that in Java, parameters are passed by value for a primitive type and by reference for a reference type (object). Why in the example below, which, in my opinion, is a reference parameter of the transfer, the point of the object does not change after replacing the method?

public class Swap2 {

    public static void swap(Point p1, Point p2) {
        Point temp = p1;
        p1 = p2;
        p2 = temp;

        System.out.println("p1.x " + p1.x);
        System.out.println("p2.x " + p2.x);                                 
    }
    /**
     * @param args
     */
    public static void main(String[] args) {
        Point p1 = new Point(100,200);
        Point p2 = new Point(300,400);
        //System.out.println("p1=" + p1.toString());
        System.out.println("p1=" + p1);     
        System.out.println("p2=" + p2);
        swap( p1, p2 );
        System.out.println("p1.x " + p1.x);
        System.out.println("p1=" + p1);
        System.out.println("p2=" + p2);    
    }    
}