After all component settings, create an ImageIcon object with your desired image. Using this object, create a JLabel. Add the Jalbel to the lowest LayeredPane of the JFrame. Finally, add the Jlabel to JPanel1, which is already added to JFrame.

Here is a sample code that shows the technique of setting image as background to a frame.

 import javax.swing.*;public class setimage extends JFrame{  public setimage()  {    super("Image Setting");    JPanel imagePanel = new JPanel ();    getContentPane ().add (imagePanel);	addWindowListener(new java.awt.event.WindowAdapter()_{public voidwindowClosing(java.awt.event.WindowEvent e)_{ System.exit(0);}});    ((JPanel)getContentPane()).setOpaque(false);    ImageIcon scenery = new ImageIcon("KERALA_SCENERY_3.JPG");    JLabel backlabel = new JLabel(scenery);    getLayeredPane().add(backlabel, _new Integer(Integer.MIN_VALUE));    imagePanel.add(backlabel);	pack ();  }  public static void main (String args[])  {    new setimage().show();  }}