Image Doesn't Show In JFrame?

I'm trying to open an image within a JFrame but the image doesn't show. The directory path is correct. The JFrame opens perfectly but no image is showing.

JFrame frame = new JFrame("IMAGE");
frame.setSize(500,500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
ImageIcon image = new ImageIcon("images/main.jpg");
JLabel label = new JLabel("", image, JLabel.CENTER);
JPanel panel = new JPanel(new BorderLayout());
panel.add( label, BorderLayout.CENTER );
frame.setVisible(true);