Capture an Image of the Desktop
R. Kevin ColeJanuary 14, 2006

The Robot Class

Beginning with JDK 1.3, the java.awt.Robot class has made it possible to gain access to an image of the desktop throught its Robot.createScreenCapture() method.

ScreenShot.java

The example below takes a snapshot of the screen and stores it in snapshot.jpg in the current directory. For a bit of added utility, there is an optional command-line parameter that causes the program to delay for a specified number of seconds prior to taking the snapshot. The delay would give you time to bring a window to the front or iconize your java command-window.

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

import javax.imageio.ImageIO;
 
/**
 * 	Save an image of the desktop to a "screenshot.jpg".
 * 	
 * 	Usage:  java ScreenShot [seconds]
 * 	seconds	- optional number of seconds to wait prior to taking
 * 		the screen picture.
 */
public class ScreenShot
{
  public static void main(String[] argv) throws Exception
  {
      if(argv.length > 0) 
      {
          try {
              long time = Long.parseLong(argv[0]) * 1000L;
              System.out.println("ScreenShot in " + argv[0] +" second(s)...");
              Thread.sleep(time);
              System.out.println("Snap!");
          } catch(NumberFormatException nfe) 
          {
              System.err.println(argv[0]+" is not a valid number of seconds.");
              System.exit(-1);
          }
      }
      Dimension size = Toolkit.getDefaultToolkit().getScreenSize();
      Robot robot = new Robot();
      BufferedImage img = robot.createScreenCapture(new Rectangle(size););
      ImageIO.write(img, "JPG", new File("screenShot.jpg"));
  }
}