import java.awt.*;
import java.io.*;
import javax.swing.*;

public class ImagePanel extends JPanel{
	
	private ImageIcon imageIcon;
	public ImagePanel(File imageFile){
		super();
		imageIcon = new ImageIcon(imageFile.getAbsolutePath());
		setPreferredSize(new Dimension(imageIcon.getIconWidth(), imageIcon.getIconHeight()));	
	}
	
	public ImagePanel(String imageFileName){
		super();
		imageIcon = new ImageIcon(imageFileName);
		setPreferredSize(new Dimension(imageIcon.getIconWidth(), imageIcon.getIconHeight()));	
	}
	
	public void paint(Graphics g){
		super.paintComponent(g);
		g.drawImage(imageIcon.getImage(),0,0,this);
	}
}

import java.awt.*;
import javax.swing.*;

public class ImagePanelDemo extends JFrame{
	
	public ImagePanelDemo(){
		super("ImagePanelDemo");
		init();
	}
	public static void main(String[] args){
		new ImagePanelDemo();
	}
	
	public void init(){
		getContentPane().add(new ImagePanel("EinsteinBike.jpg"), BorderLayout.CENTER);
		pack();
		setLocationRelativeTo(null);
		show();
	}
}