Using Java to send key combinations

Question

As per this previous link (How to send keyboard outputs) Java can simulate a key being pressed using the Robot class. However, how could a combination of key presses be simulated? If I wanted to send the combination "alt-123" would this be possible using Robot?

Answer 1

The simple answer is yes. Basically, you need to wrap the keyPress/Release of the Alt around the other keyPress/Releases

public class TestRobotKeys {

    private Robot robot;

    public static void main(String[] args) {
        new TestRobotKeys();
    }

    public TestRobotKeys() {
        try {
            robot = new Robot();
            robot.setAutoDelay(250);
            robot.keyPress(KeyEvent.VK_ALT);
            robot.keyPress(KeyEvent.VK_1);
            robot.keyRelease(KeyEvent.VK_1);
            robot.keyPress(KeyEvent.VK_2);
            robot.keyRelease(KeyEvent.VK_2);
            robot.keyPress(KeyEvent.VK_3);
            robot.keyRelease(KeyEvent.VK_4);
            robot.keyRelease(KeyEvent.VK_ALT);
        } catch (AWTException ex) {
            ex.printStackTrace();
        }
    }

}

Answer 2

For sending keys combination using java.awt.Robot the following code works fine for me

import java.awt.AWTException;
import java.awt.Robot;
import java.awt.event.KeyEvent;



public class VirtualKeyBoard extends Robot
{

    public VirtualKeyBoard() throws AWTException
    {
        super();
    }

    public void pressKeys(String keysCombination) throws IllegalArgumentException
    {
            for (String key : keysCombination.split("\\+"))
            {
                try
                {   System.out.println(key);
                    this.keyPress((int) KeyEvent.class.getField("VK_" + key.toUpperCase()).getInt(null));

                } catch (IllegalAccessException e)
                {
                    e.printStackTrace();

                }catch(NoSuchFieldException e )
                {
                    throw new IllegalArgumentException(key.toUpperCase()+" is invalid key\n"+"VK_"+key.toUpperCase() + " is not defined in java.awt.event.KeyEvent");
                }


            }


    }


    public void releaseKeys(String keysConbination) throws IllegalArgumentException
    {

            for (String key : keysConbination.split("\\+"))
            {
                try
                { // KeyRelease method inherited from java.awt.Robot
                    this.keyRelease((int) KeyEvent.class.getField("VK_" + key.toUpperCase()).getInt(null));
                } catch (IllegalAccessException e)
                {
                    e.printStackTrace();
                }catch(NoSuchFieldException e )
                {
                    throw new IllegalArgumentException(key.toUpperCase()+" is invalid key\n"+"VK_"+key.toUpperCase() + " is not defined in java.awt.event.KeyEvent");
                }
            }


    }

    public static void main(String[] args) throws AWTException
    {


         VirtualKeyBoard kb = new VirtualKeyBoard();


         String keyCombination = "control+a"; // select all text on screen
         //String keyCombination = "shift+a+1+c"; // types A!C on screen

         // For your case 
         //String keyCombination = "alt+1+2+3";


         kb.pressKeys(keyCombination);
         kb.releaseKeys(keyCombination); 



    }


}