Declare a variable typed "name of a class"-Need help

Question

I have "segment" class in package named Ex13
import Exercise12.Point123;
public class segment {
     private Point123 start;
     private Point123 end;
     public segment(Point123 start, Point123 end) {
          this.start = start;
          this.end = end;
     public double length() {
          return start.distance(end.getX(), end.getY());
     public String midlePoint() {
          return (end.getX() + start.getX()) / 2 + " "
                    + (end.getY() + start.getY()) / 2;
          // return insidePoint(1,1);
     public Point123 insidePoint(double m, double n) {
          double ratio = m / (m + n);
          return new Point123(start.getX()+(end.getX() - start.getX()) * ratio,
                    start.getY()+(end.getY() - start.getY()) * ratio);
//return (start.getX()+(end.getX() - start.getX())*ratio);
}And class "Point123" in package Ex12:
public class Point123 {
     private double x;
     private double y;
     public Point123(double xAsis, double yAsis) {
          x = xAsis;
          y = yAsis;
     public double getX() {
          return x;
     public double getY() {
          return y;
//     public String toString() {
//          return String.format("%.1f,%.1f", x, y);
     public boolean isOrigin() {
          return x == 0 && y == 0;
     public boolean isOnX_Axis() {
          return y == 0;
     public boolean isOnY_Axis() {
          return x == 0;
     public double distance(double xAsis, double yAsis) {
          return Math.sqrt(Math.pow(xAsis - x, 2) + Math.pow(yAsis - y, 2));
}I remove toString method in Point123 class, but whenever I call insidePoint method in segment class it print out "Exercise12.Point123@addbf1". In other hand, I don't remove toString method, I call insidePoint method,then it prints out the correct result which I want.
I think the reason why this thing happened is that I am using Point123 return type in insidePoint method. To midlePoint method in segment class, it does not affect whether I remove toString or not. That is because I use its own String return type.
Can someone tells me whether my thought is correct or not? And explain more about variable typed "name of a class"

Answer 1

Oh! My header's segment class does not have extend...., therefore it inherit from the Object. But what is Object in my class?
is it "*s*" in my code?
public class DisplayResult {
     public static void main(String[] args) {
               segment s  = new segment(new Point123(3,4), new Point123(6,7));
               System.out.println(s.length());
               System.out.println(s.midlePoint());
               System.out.println(s.insidePoint(1.5,4));
}