import java.awt.image.BufferedImage;
import java.awt.Image;
import java.io.File;
import java.io.IOException;
import java.util.Iterator;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;

public class ImageReaderTest1 {
    public ImageReaderTest1() {}

    public ImageReaderTest1(String filename) {
        Image image = readImage(filename);
        initFrame(filename, image);
    }

    protected Image readImage(String filename) {
        Iterator readers = ImageIO.getImageReadersBySuffix(getSuffix(filename));
        
        if (readers.hasNext()) {
            ImageReader reader = (ImageReader)readers.next();
            
            try {
                ImageInputStream stream = ImageIO.createImageInputStream(new File(filename));
                reader.setInput(stream);

                Image image = reader.read(0);
                reader.dispose();

                return image;
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }

        return null;
    }
    
    protected void initFrame(String imageName, Image image) {
        if (image != null) {
            JFrame frame = new JFrame(imageName);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

            ImageIcon icon = new ImageIcon(image);
            JLabel label = new JLabel(icon);
        
            frame.getContentPane().add(new JScrollPane(label));
            frame.pack();
            frame.setVisible(true);
        }
    }

    protected String getSuffix(String filename) {
        int i = filename.lastIndexOf('.');
        if(i>0 && i<filename.length()-1) {
            return filename.substring(i+1).toLowerCase();
        };
        
        return "";
    }

    public static void main(String[] args) {
        if (args.length == 1) {
            new ImageReaderTest1(args[0]);
        } else {
            System.out.println("Usage: java ImageReaderTest1 <filename>");
        }
    }
}