Java Threads

Hi - I have a slight issue with threads. I'm also new to Java so
bear with me if I've done anything stupid!

There are two main classes: Main and FxThread.

FxThread extends Thread and implements Runnable and Main creates three
threads, gets them to run and sticks them in an array with the threads
running in a "while true" loop.

Now, the code all works, but it eats the CPU like there is no tomorrow.
CPU usage actually shoots up to 100% when I run it.

Why is this?

Any help would be much appreciated. Thanks in advance!


------------------------------
public class FxThread extends Thread implements Runnable{

String data;

FxThread(){
data = "this is some data";
}

public void run(){
int i = 0;
while (true)
{
i++;
}
}
}
------------------------------------
public static void main (String [] args)
{

FxThread [] array = new FxThread[3];

FxThread thread = new FxThread();
FxThread thread1 = new FxThread();
FxThread thread2 = new FxThread();

thread.start();
array[0] = thread;

thread1.start();
array[1] = thread1;

thread2.start();
array[2] = thread2;

}
-------------

.