Java tutorial
import java.awt.Graphics; import java.awt.Image; import java.awt.Toolkit; import java.io.IOException; import javax.swing.JPanel; public class Main extends javax.swing.JFrame { Image backgroundImage = Toolkit.getDefaultToolkit().getImage("mong.jpg"); public Main() throws IOException { this.setContentPane(new JPanel() { @Override public void paintComponent(Graphics g) { super.paintComponent(g); g.drawImage(backgroundImage, 0, 0, null); } }); pack(); setVisible(true); } public static void main(String[] args) throws Exception { new Main(); } }