Exit the JVM

SafeExitJVM_snippet.java

/**
 * Exits the JVM using {@code Runtime.getRuntime().exit(status)} (which is equivalent to
 * {@code System.exit(0)}). If something goes wrong while running the finalizers and shutdown
 * hooks, or the timeout is reached, the JVM is forced to be terminated by calling
 * {@code Runtime.getRuntime().halt(status)}.
 * 
 * @param status the exit status, zero for OK, non-zero for error
 * @param timeout The maximum delay in milliseconds before calling
 *            {@code Runtime.getRuntime().halt(status)}.
 * 
 * @see <a href="http://blog.joda.org/2014/02/exiting-jvm.html">exiting jvm</a>
 */
public static void exit(int status, long timeout) {
	final Runtime runtime = Runtime.getRuntime();
	try {
		schedule(() -> runtime.halt(status), timeout);
		runtime.exit(status);
	} catch (Throwable x) {
		runtime.halt(status);
	} finally { // double-check
		runtime.halt(status);
	}
}

/**
 * Syntactic sugar, allows to call
 * 
 * <pre>
 * <code>
 * final Timer timer = Timers.schedule(() -&gt; println("hi"), 1000)
 * </code>
 * </pre>
 * 
 * instead of
 * 
 * <pre>
 * <code>
 * final Timer timer = new Timer();
 * timer.schedule(new TimerTask() {
 *     &#64;Override
 *     public void run() {
 *         println("hi");
 *     }
 * }, 1000);
 * </code>
 * </pre>
 * 
 * @param task A Runnable
 * @param delay A delay in milliseconds
 * @return A Timer
 */
public static Timer schedule(Runnable task, long delay) {
	final Timer timer = new Timer();
	timer.schedule(new TimerTask() {
		@Override
		public void run() {
			task.run();
		}
	}, delay);
	return timer;
}