import java.awt.image.BufferedImage;
import java.net.URL;
import java.util.Iterator;
import javax.imageio.ImageIO;
import javax.imageio.ImageReader;
import javax.imageio.stream.ImageInputStream;
public class Main {
public static void main(String[] argv) throws Exception {
ImageInputStream imageStream = ImageIO.createImageInputStream(new URL("").openStream());
Iterator readers = ImageIO.getImageReaders(imageStream);
ImageReader reader = null;
if (!readers.hasNext()) {
imageStream.close();
return;
} else {
reader = readers.next();
}
String formatName = reader.getFormatName();
if (!formatName.equalsIgnoreCase("jpeg") && !formatName.equalsIgnoreCase("png")
&& !formatName.equalsIgnoreCase("gif")) {
imageStream.close();
return;
}
reader.setInput(imageStream, true, true);
BufferedImage theImage = reader.read(0);
reader.dispose();
imageStream.close();
}
}