JavaMan:
Get rid of that Serial.list()[0] line (who started that nonsense, anyway?). Replace portName with "COM3" or whatever port your Arduino uses. This works on my computer:// the name of port connecting the arduino
myPort = new Serial(this, "COM6", 9600);
Serial.list()[0] works on my computer, using a different operating system. There's no such thing as "COM6" on my computer. So why should OP change to using something that has to be changed for every computer he's on, rather than something that's even cross-kernel compatible?
Note that on unix environments, the location of the com port can change if you unplug-and-replug a device too quickly -- so the arduino may be on /dev/ttyACM0 and when unplug it and plug it back in, it'll be on /dev/ttyACM1. I don't want to have to figure out where it is and change the program accordingly when the program can do it itself.
Or is there a language called Processing?
Yes. It's what the arduino IDE is based off of. Many people use them together.