public class Test {
    private static boolean b;
    private static int i = 1;

    public static void main(String[] args) throws InterruptedException {

        Thread thread = new Thread(new Runnable() {

            @Override
            public void run() {
                while (!b) {
                    System.out.println(i);
                }
            }
        });
        thread.start();

        TimeUnit.SECONDS.sleep(1);
        b = true;
        i = 2;
        System.out.println(b);
    }
}