Java Executor proper shutdown

executor-shutdown.java

	try {
	    System.out.println("attempt to shutdown executor");
	    executor.shutdown();
	    executor.awaitTermination(5, TimeUnit.SECONDS);
	}
	catch (InterruptedException e) {
	    System.err.println("tasks interrupted");
	}
	finally {
	    if (!executor.isTerminated()) {
	        System.err.println("cancel non-finished tasks");
	    }
	    executor.shutdownNow();
	    System.out.println("shutdown finished");
	}