Java Robot Class Using Variables

Question

I have a very simple question, or at least I think it is simple. Currently I'm trying to use the robot class with variables. What I mean by this is the following (the variables "pass" are chars.)

            pass1 = 0;
            pass2 = 0;
            pass3 = 0;
            pass4 = 0;


                try{
                        Robot robot = new Robot(); 
                        robot.delay(2000);

                        robot.mouseMove(1318, 322);
                        robot.keyPress(pass1);
                        robot.keyPress(pass2);
                        robot.keyPress(pass3);
                        robot.keyPress(pass4);
                        } catch (AWTException e) {e.printStackTrace();}

When I run the program, I get this error (keep in mind I only get this error when the portion of the code with "pass1, pass2...etc." is in it.):

Exception in thread "AWT-EventQueue-0" java.lang.IllegalArgumentException: Invalid key code
at java.awt.Robot.checkKeycodeArgument(Unknown Source)
at java.awt.Robot.keyPress(Unknown Source)
at Cracker$2.mouseReleased(Cracker.java:117)
at java.awt.AWTEventMulticaster.mouseReleased(Unknown Source)
at java.awt.Component.processMouseEvent(Unknown Source)
at javax.swing.JComponent.processMouseEvent(Unknown Source)
at java.awt.Component.processEvent(Unknown Source)
at java.awt.Container.processEvent(Unknown Source)
at java.awt.Component.dispatchEventImpl(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)
at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)
at java.awt.Container.dispatchEventImpl(Unknown Source)
at java.awt.Window.dispatchEventImpl(Unknown Source)
at java.awt.Component.dispatchEvent(Unknown Source)
at java.awt.EventQueue.dispatchEventImpl(Unknown Source)
at java.awt.EventQueue.access$000(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.awt.EventQueue$3.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.awt.EventQueue$4.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

Robot#keyPress expects an int, which represents the virtual key code as described in java.awt.KeyEvent

Specifically, key 0 represents KeyEvent.VK_UNDEFINED which is an "invalid key code"

Don't forget that until you call keyRelease, the keys will continue to be pressed, generating repeated key pressed events...