import java.awt.Rectangle;
import java.awt.Robot;
import java.awt.Toolkit;
import java.awt.image.BufferedImage;
import java.io.File;

import javax.imageio.IIOImage;
import javax.imageio.ImageIO;
import javax.imageio.ImageWriteParam;
import javax.imageio.ImageWriter;
import javax.imageio.stream.FileImageOutputStream;

public class ScreenShot{
	public static void main(String[] args){
		File arquivo = new File("C:\\SS.jpg");
		
		try {
			Robot robot = new Robot();
			
			Rectangle rect = new Rectangle(Toolkit.getDefaultToolkit().getScreenSize());
			
			BufferedImage img = robot.createScreenCapture(rect);
			ImageWriter writer = ImageIO.getImageWritersByFormatName("jpeg").next();
			ImageWriteParam iwp = writer.getDefaultWriteParam();
			iwp.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
			iwp.setCompressionQuality(1);
			
			writer.setOutput(new FileImageOutputStream(arquivo));

			IIOImage iioimage = new IIOImage(img, null, null);
			
			writer.write(null, iioimage, iwp);
			writer.dispose();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}