public class ExampleSignalHandler {
    public static void main(String... args) throws InterruptedException {
        final long start = System.nanoTime();
        Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
            public void run() {
                System.out.format("\nProgram execution took %f seconds\n", (System.nanoTime() - start) / 1e9f);
            }
        }));
        int counter = 0;
        while(true) {
            System.out.println(counter++);
            Thread.sleep(500);
        }
    }
}