Moving a graphic object in Java

salam
I have the same problem and I tried with this program but I don't know how to specify the distance values between the vertices and how to draw the triangles of the arrows?
import java.awt.*; // import class Graphics
import javax.swing.*; // import package javax.swing
import java.util.*;
import java.awt.Graphics;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class po extends JPanel { int []corX;
int[] corY;int i;
public po(){
corX=new int[9];
corY=new int[9];
Random r=new Random();

for (int i=0;i<7;i++){
corX[i]=r.nextInt(600);//chooses a number from 1 to 600 for the i-th case
corY[i]=r.nextInt(400) ;
System.out.println ("cox["+i+"]="+ corX[i]);
System.out.println ("coy["+i+"]="+ corY[i]);
}}
public void paint(Graphics g)
{
for (int i=0;i<7;i++){
g.setColor(Color.white);
g.fillOval(corX[i],corY[i],30,30);
g.setColor(Color.blue);
g.drawString(""+i,corX[i]+15,corY[i]+15);
}
g.setColor(Color.white);
for(int i=0;i<6;i++)
{ g.drawLine(corX[i]+30,corY[i]+15,corX[i+1]+30,corY[i+1]+15);
// Polygon triangle = new Polygon(new int[] {corX[i+1]+30,corX[i+1]+40,corX[i+1]+50},new int[] {corY[i+1]+30,corY[i+1]+20,corY[i+1]+30},3);
//g.drawPolygon(new int[] {corX[i+1]+30,corX[i+1]+30,corX[i+1]+50},new int[] {corY[i+1]+15,corY[i+1]+40,corY[i+1]+50},3);
} }
public static void main (String[] args) {
JFrame frame = new JFrame();
frame.setBackground(Color.black);
frame.getContentPane().add(new po());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(200,200);
frame.setVisible(true);
}
}
thank you in advance
please help me