Thread: Graphics2D Exception

Graphics2D  graphics;
 
graphics.fillOval(x1,y1,x2,y2);

The .java program compiles with no errors.
However. when I try to run it I get a long list of exceptions when it comes to the above code,
headed by

Exception in thread "AWT-EventQueue-0" java.lang Null PointerException .... and much more.

Any help will be appreciated.

Originally Posted by copeg

Not enough information to pinpoint the issue aside from a) given that graphics is not instantiated in the two lines of code you posted, it is assigned the default value of null b) if the graphics object is null it is suggestive that you are doing custom painting incorrectly. My advice a) add some println's to figure out the variable that is null, and then backtrack to determine why it is null b) post an SSCCE so your code can be more thoroughly evaluated.

Herewith relevant code.

 
class Jexp3 extends JPanel implements MouseListener
{
  int  mouseX, mouseY;
  int width, height;
  Graphics2D graphics;
  Color color;
  public Jexp3()
  {
        super();
        setLayout(null);
        addMouseListener(this);
  }        
  public void mouseClicked(MouseEvent m){
      mouseX = m.getX();
      mouseY = m.getY();
      color = Color.red;
      width = (int)getSize().getWidth();
      height = (int)getSize().getHeight();
      graphics.fill (new Ellipse2D.Float (mouseX, mouseY, 25, 25));
      System.out.println("Mouse Clicked "+ mouseX + " " + mouseY);
  }