addShutdownHook() of Runtime class

The addShutdownHook method of Runtime class is vervy useful to invoke something before a application exit. In addition coding in JUnit, very useful. 

If you create and use some Threads,  you can not invoke directly, this method usage is very helpful. 

public class Monitor {

private static Log log = LogFactory.getLog(HTMLPageFetcher.class);

private static NotificationCollector notiCollector;

static {

Runtime.getRuntime().addShutdownHook(new Thread() {

public void run() {

close();

}

});

}

public static void close() {

log.info("close application.!!");

notiCollector.stop();

}


...