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

This is an example

Robot r = new Robot();
Thread.sleep(1000);

r.keyPress(KeyEvent.VK_ALT);
r.keyPress(KeyEvent.VK_NUMPAD1);
r.keyPress(KeyEvent.VK_NUMPAD2);
r.keyPress(KeyEvent.VK_NUMPAD3);            
r.keyRelease(KeyEvent.VK_ALT);

Don't forget to release some special keys, it will make some crazy things on your machine

Answer 3

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); 



    }


}

Answer 4

This code is too close to native windows keyboard. Even Api keyboard "presses" are coming into Eclipse ide as those would pressed normally from ide. Keys was produced from current debugged application!! (jdk 1.8, win 7, hp)