Java determine pixel was clicked or not

Complete source code below just a simple java program that will determine if you was clicked or not on 8 black dots. If you was clicked , program will inform you that the dot was clicked.I hope you can see all 8 black dots that i mean because it is too small and try click on it to see what happen.

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COMPLETE SOURCE CODE FOR : JavaDeterminePixelClicked.java
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::Click Here To Download This Java Source Code::

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class JavaDeterminePixelClicked extends Canvas implements MouseListener
{
 boolean [] con={ false,false,false,false,false,false,false,false };
 int[][]coor=new int[8][2];
 Robot r;
 
 public JavaDeterminePixelClicked()
 {
  addMouseListener(this);
  try
  {
   r=new Robot();
  }
  catch(Exception exception)
  {
   exception.printStackTrace();
  }

  JFrame a=new JFrame(">>>>>TRY CLICK AT BLACK DOT<<<<<");
  a.getContentPane().add(this,BorderLayout.CENTER);
  a.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
  a.setSize(500,500);
  a.setLocationRelativeTo(null);
  a.setVisible(true);
 }
 
 public void paint(Graphics g)
 {
  setBackground( new Color (255,255,255) );
  super.paint(g);
  g.setColor( new Color (0,0,0) );
  g.drawLine(30,30,30,30);
  g.drawLine(40,40,40,40);
  g.drawLine(50,50,50,50);
  g.drawLine(60,60,60,60);
  g.drawLine(70,70,70,70);
  g.drawLine(80,80,80,80);
  g.drawLine(90,90,90,90);
  g.drawLine(100,100,100,100);
 }
 
 public void mouseClicked(MouseEvent event)
 {
  Color temp=r.getPixelColor(event.getLocationOnScreen().x,event.getLocationOnScreen().y);
  if(temp.getRed()==0&&temp.getGreen()==0&&temp.getBlue()==0)
  {
   int upperLeftX=getLocationOnScreen().x;
   int upperLeftY=getLocationOnScreen().y;
   int currentX=event.getLocationOnScreen().x;
   int currentY=event.getLocationOnScreen().y;
   if(currentX-upperLeftX==30&¤tY-upperLeftY==30)
   {
    if(con[0]==false)
    {
     con[0]=true;
    }
    else
    {
     JOptionPane.showMessageDialog(null,"This point was clicked");
    }
   }
   if(currentX-upperLeftX==40&¤tY-upperLeftY==40)
   {
    if(con[1]==false)
    {
     con[1]=true;
    }
    else
    {
     JOptionPane.showMessageDialog(null,"This point was clicked");
    }
   }
   if(currentX-upperLeftX==50&¤tY-upperLeftY==50)
   {
    if(con[2]==false)
    {
     con[2]=true;
    }
    else
    {
     JOptionPane.showMessageDialog(null,"This point was clicked");
    }
   }
   if(currentX-upperLeftX==60&¤tY-upperLeftY==60)
   {
    if(con[3]==false)
    {
     con[3]=true;
    }
    else
    {
     JOptionPane.showMessageDialog(null,"This point was clicked");
    }
   }
   if(currentX-upperLeftX==70&¤tY-upperLeftY==70)
   {
    if(con[4]==false)
    {
     con[4]=true;
    }
    else
    {
     JOptionPane.showMessageDialog(null,"This point was clicked");
    }
   }
   if(currentX-upperLeftX==80&¤tY-upperLeftY==80)
   {
    if(con[5]==false)
    {
     con[5]=true;
    }
    else
    {
     JOptionPane.showMessageDialog(null,"This point was clicked");
    }
   }
   if(currentX-upperLeftX==90&¤tY-upperLeftY==90)
   {
    if(con[6]==false)
    {
     con[6]=true;
    }
    else
    {
     JOptionPane.showMessageDialog(null,"This point was clicked");
    }
   }
   if(currentX-upperLeftX==100&¤tY-upperLeftY==100)
   {
    if(con[7]==false)
    {
     con[7]=true;
    }
    else
    {
     JOptionPane.showMessageDialog(null,"This point was clicked");
    }
   }
  }
 }
 
 public void mouseEntered(MouseEvent event)
 {
  //NOTHING
 }
 
 public void mouseExited(MouseEvent event)
 {
  //NOTHING
 }
 
 public void mousePressed(MouseEvent event)
 {
  //NOTHING
 }
 
 public void mouseReleased(MouseEvent event)
 {
  //NOTHING
 }
 
 public static void main(String[]args)
 {
  JavaDeterminePixelClicked jdpc = new JavaDeterminePixelClicked ();
 }
}

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JUST COMPILE AND EXECUTE IT
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