JComponent needs to be painted on creation

Question

I have a Card class that extends JComponent. The paintComponent method is implemented. Added it to a JPanel. Added the JPanel to the JFrame. The JComponent only shows up when the frame is resized, not when the frame is first shown on screen. The only fix I can think of is to place a method in the constructor of JComponent that paints itself on creation. Has anyone had this problem before?
public Card(Rank rank, Suit suit, String img) {
        super();
        this.rank = rank;
        this.suit = suit;
        this.image = Toolkit.getDefaultToolkit().createImage(img);
     setPreferredSize(new Dimension(400, 300));
     setVisible(true);
public void paintComponent(Graphics g) {
boolean x = g.drawImage(this.image, getX(), getY(), null);
}

Answer 1

If I'm not mistaken, the Toolkit#createImage() methods do asynchronous loading of the image, so when your JFrame is being displayed, the image hasn't been fully loaded yet. Use a method of loading the image that blocks until it's complete, such as ImageIO. Here's a working example:
import java.awt.*;
import java.io.*;
import javax.imageio.ImageIO;
import javax.swing.*;
public class ImageJPanelTest extends JFrame {
     public ImageJPanelTest() {
          JPanel contentPane = new Card();
          setContentPane(contentPane);
          setDefaultCloseOperation(EXIT_ON_CLOSE);
          setTitle("Image JPanel Test");
          pack();
     public static void main(String[] args) {
          SwingUtilities.invokeLater(new Runnable() {
               public void run() {
                    new ImageJPanelTest().setVisible(true);
     class Card extends JPanel {
          private Image image;
          public Card() {
               String img = "anchor.png";
               // Commented-out line requires the frame to be resized/moved/etc.
               // before image is shown.  The lines following it show the image
               // immediately.
               //image = Toolkit.getDefaultToolkit().createImage(img);
               try {
                    image = ImageIO.read(new File(img));
               } catch (IOException ioe) {
                    ioe.printStackTrace();
                    image = null; // Create a default image to prevent NPE later
               setPreferredSize(new Dimension(400, 300));
          public void paintComponent(Graphics g) {
               g.drawImage(image, 0,0, null);//getX(), getY(), null);
}