How to simulate Keyboard press in java

Question

I want to simulate entering a string (can contain any character) in JTextField. I am using new KeyEventData() for that. But I am not able to determine how to handle characters like {, }, ) etc and also how to append a new character to already entered characters.

score 5 · Accepted Answer · edited May 23 '17 at 10:34

5

You can use Robot for this, as shown in this example. To get {, for example, you'll need to do something like this:

keyPress(KeyEvent.VK_SHIFT);
keyPress(KeyEvent.VK_OPEN_BRACKET);
keyRelease(KeyEvent.VK_OPEN_BRACKET);
keyRelease(KeyEvent.VK_SHIFT);

edited May 23 '17 at 10:34

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answered Aug 31 '12 at 20:50

trashgod

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so for every character i need to check its value and based on that decide whether to use shift or not. – user1247412 Aug 31 '12 at 21:00
Yes, `KeyEvent` instances are low level events. – trashgod Aug 31 '12 at 21:09
when I use the above code for VK_PLUS, i get invalid key code exception – user1247412 Aug 31 '12 at 21:33
On my keyboard, `VK_PLUS` is unshifted, while shift-`VK_EQUALS` yields a plus sign. – trashgod Aug 31 '12 at 21:39

score 2 · Answer 2 · edited May 23 '17 at 12:18

2

This might be helpful for emulating keyevents: How to simulate keyboard presses in java?

For left and right brace, KeyEvent.VK_BRACELEFT and KeyEvent.VK_BRACERIGHT http://docs.oracle.com/javase/7/docs/api/java/awt/event/KeyEvent.html#VK_BRACELEFT

Hope this helps =]

edited May 23 '17 at 12:18

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answered Aug 31 '12 at 20:29

corgichu

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@ cskoala: I am not able to determine which key to press at runtime and how to append key character to already typed string. – user1247412 Aug 31 '12 at 20:31
Sorry, what exactly are you trying to do? I thought you just wanted to simulate entering a string? Are you waiting for user input at runtime or are you putting which keys to press in your code? – corgichu Aug 31 '12 at 20:34
I take an input from string. Then I want to simulate that value to be typed in a JTextField. – user1247412 Aug 31 '12 at 20:41
oh okay, so can't you parse the String character by character then have a switch statement with each possible character and simulate the key presses that way? – corgichu Aug 31 '12 at 20:48
do you think that'll work for you? if so and you're confused, I can provide a small sample. – corgichu Aug 31 '12 at 20:48
Actually I got your point, only thing I am worried is that will be a lengthy code. – user1247412 Aug 31 '12 at 21:31
Yeah, it would be pretty lengthy, but a switch statement would be the only way to differentiate which keyPress to simulate since you have to use a different KeyEvent.VK for each different character. – corgichu Aug 31 '12 at 21:53

score 1 · Answer 3 · answered Aug 31 '12 at 20:33

check VK_BRACELEFT, VK_BRACERIGHT, VK_RIGHT_PARENTHESIS and VK_LEFT_PARENTHESIS for handling those characters.

For the appending the character, you might suppose building the list of characters or building the string.

edit: for getting the character value from the keyevent try KeyEvent.getKeyChar()

How to simulate Keyboard press in java

3 Answers3

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