My problem is that I want to draw a dashed line in a panel, I\'m able to do it but it draw my border in dashed line as well, which is oh my god!
Can someone please e
You're modifying the Graphics instance passed into paintComponent(), which is also used to paint the borders.
Instead, make a copy of the Graphics instance and use that to do your drawing:
public void drawDashedLine(Graphics g, int x1, int y1, int x2, int y2){
//creates a copy of the Graphics instance
Graphics2D g2d = (Graphics2D) g.create();
//set the stroke of the copy, not the original
Stroke dashed = new BasicStroke(3, BasicStroke.CAP_BUTT, BasicStroke.JOIN_BEVEL, 0, new float[]{9}, 0);
g2d.setStroke(dashed);
g2d.drawLine(x1, y1, x2, y2);
//gets rid of the copy
g2d.dispose();
}