How can I detect a key press from the system console in Java before the 'enter' key is pressed?

Question

I am working on a Java application that gets input and sends output to the system console (System.out and System.in). I need to detect the pressing of a certain key right when it is pressed... not once the user presses enter.

For example, say I need to detect the pressing of the 'A' key, and when that happens, the program will do System.out.println("YOU PRESSED THE A KEY");

If a user tries to type the word "roman" this will happen:

romaYOU PRESSED THE A KEY
n

I hope that makes sense. I know there is no method for doing this, but any work around would do, including creating an invisible component to implement a KeyListener (though from what I have seen, components can only listen for keys if they are visible). Also, I need to do this using pure Java, not system-specific libraries.

Thanks very much to anyone who can help!

>You need to output a terminal control sequence
>to switch to cbreak mode instead of the default
>line-buffered mode. Then you can read
>characters immediately instead of entire lines.

Thanks very much to the speedy reply, but can you be a little more specific about how to do this?

>I think this is what you are looking for
>Source(s):
>http://www.particle.kth.se/~fmi/kurs/phy...
Sorry, that doesn't work. It still waits for the user to press enter rather than reading in each character as it is typed.

>simple catch the keypressed event
>Source(s):
>Find Computer Tutorials, Software
>Books,Interview Question And Answer at
>http://myitcareer.org/

As I said before, only componenets can implement KeyListener, and then they can only catch KeyEvents if they are visible and in focus. Did you even read my question?

Answer 1

You need to output a terminal control sequence to switch to cbreak mode instead of the default line-buffered mode. Then you can read characters immediately instead of entire lines.

Answer 2

simple catch the keypressed event

Answer 3

I think this is what you are looking for