java console key listening?

Hobbes

I want to create a loop that breaks out when the user presses Q (I have threads running in this loop).

The loop is in the main, but I am not sure how monitor for keyboard output. Tried using the AWT keylistener but that looks like it needs to be mapped to a component. Or maybe doing something wrong.

$lash

Cant see why keyListener wouldnt work for this...

MrPinK

Off the top of my head I'd try...

while (!done)
{  
    char c = (char)(System.in.read());
    if (c == 'Q' || c == 'q')
    {
        done = true;
        // stop other threads
    }
}

You may need to catch IOExceptions too

enda_4

Is it a frame your using?

did you try adding the keylistener to the component

"component".addkeylistener(this)

public void keyTyped(KeyEvent e)
{
char keyTyped=e.getKeyChar(); // read input
System.out.println(keyTyped); // just to check it working
chkLetter(keyTyped); // send to a function to check the letter

}

// Check for letters in array
public void chkLetter(char keyTyped)
{
for (int i=0; i >1 ; i++) // infinite loop just
{
if(keyTyped == 'Q')
break;
}
}

Code mightn't be 100%, but something similar should do it

Hobbes

It is the main() I am doing it from. MrPink, what you had I tried before (or something similar). The problem is that read() reads a line and not a character. So the program will wait for the enter key to be pressed. So you can't have a loop as such.

MrPinK

Yeah, that's the closest that you can get to it in java. If you want to catch a single key press then you can't use the console, it'd have to be a GUI.

Unless of course you write some C code and have your Java prog call it from a DLL

Draupnir

You could always build your own Console Reading class which you could then use to read a single character and return its value. But I guess maybe thats not what you want to do.

By the way, you probably already have it, but there is a console reader class pretty readily available which you can use to read input to the console easily. if ya need it, drop me a pm ill send you the .class file.

if im totally missing the point then excuse me

Hobbes

Thanks guys. Actually wanted to use Java as is to create it. But no matter. Will convert it to SWT.