关于在同一个文件中两个源程序相联系的显示问题

程序一 是显示点
程序二 是显示线，也就是两个点的连接
程序二要引用程序一的东西 所以源程序是放在同一个文件下的
问题是我想在程序二里输出线的情况 但输出的结果还是程序一里点的情况
请问应该怎么改代码



程序一
package point3d;


public class Point3d {
int x;
int y;
int z;

public Point3d(){}
public Point3d(int a,int b,int c){
x=a;
y=b;
z=c;

}
public Point3d(int a,int b){
x=a;
y=b;
}
public String toString(){
return"点："+x+","+y+","+z;
}

public static void main(String[] args) {
Point3d p0=new Point3d();
Point3d p1=new Point3d(1,2,3);
Point3d p2=new Point3d(2,3);

System.out.println("point"+p0);
System.out.println("point"+p1);
System.out.println("point"+p2);
}

}

程序二
package point3d;

public class Line3d {
Point3d pa;
Point3d pb;


public Line3d(){}
public Line3d(Point3d a,Point3d b){
pa=a;
pb=b;

}
public String toString(){
return"直线：从"+pa+"到"+pb;
}
public static void main(String[] args) {
Point3d p1=new Point3d(1,2,3);
Point3d p2=new Point3d(2,3);
Line3d r1=new Line3d();
Line3d r2=new Line3d(p1,p2);


System.out.println("line"+r1);
System.out.println("line"+r2);
}
}