Shutdown Application Gracefully

Question

Hi,
I have multiple threads running in application. Before killing application (forcefully), I want to make sure all threads have executed successfully. Following is the code abstract:
    public class MainClass {
    private static Thread1;
    private static Thread2;
    public static void main(String args[]) {
        thread1 = new Thread1();
        thread2 = new Thread2();
public class Thread1 implements Runnable {
    private ThreadPoolExecutor threadPoolExecutor;
    private final LinkedBlockingQueue<Runnable> blockingQueue = new LinkedBlockingQueue<Runnable>();
    public Thread1() {
        threadPoolExecutor = new ThreadPoolExecutor(10,100, 50000, TimeUnit.SECONDS, blockingQueue);
        Thread thread = new Thread(this);
        thread.start();
    public void run() {
        // some processing...
public class Thread2 implements Runnable {
    private ThreadPoolExecutor threadPoolExecutor;
    private final LinkedBlockingQueue<Runnable> blockingQueue = new LinkedBlockingQueue<Runnable>();
    public Thread2() {
        threadPoolExecutor = new ThreadPoolExecutor(10,100, 50000, TimeUnit.SECONDS, blockingQueue);
        Thread thread = new Thread(this);
        thread.start();
    public void run() {
        // some processing...
}Requirement is that all executing threads must be able to finish their task before the MainClass is stopped. Any help, with appropriate example, would be appreciated.
PS: I'm using Springframework too.

Answer 1

Dear TechSawi,
I am still a concurrency student and not an expert, but perhaps this could help.
In Java 5 there are some new components/tools for concurrency that seem very usefull. One of those is a CyclicBarrier. A CyclicBarrier lets you run an amounts of threads and the barrier has a blocking thread as well. The blocking thread is only executed when all the other threads are finished.
I have almost no experience with this object, but perhaps if you lookup how it works it might be of help. I have no idea if it will be usefull at all...
salutations,
Nicholas