Question

I have many facilities. Whenever facilities are turned on they call some class so that they can run at fixed Scheduled rate. If the facilities is closed i need to shutdown thread for that particular facility. How can i achieve that i am getting RejectedExecutionException when i try to shutdown and reopen the same facility later . Thanks for help. My code is similiar like as follows:

 private static final ScheduledExecutorService svc = Executors
        .newSingleThreadScheduledExecutor();
private static ScheduledFuture<?> syncThreadHandle = null;

public static void start(final String str1, final String str2) {

    syncThreadHandle = svc.scheduleAtFixedRate(new Runnable() {
        @Override
        public void run() {
            System.out.println("First string for this thread str1 " + str1
                    + " Str2 " + str2);
        }

    }, 0, 1, TimeUnit.MINUTES);
}

public static void stop(final String str1, final String str2) {
    svc.shutdown();
}

// and from another class i am using this.

 public static void main(String args[])
      {

    ProcessFixedRun.start("hi", "hello");
    ProcessFixedRun.start("hi agaIN", "hello again");
    ProcessFixedRun.stop("hi", "hello");

}

How can i find the thread for that particular facility. I am not good at threads. Any help will be appreciated thanks

Answer 1

Can you store the ScheduleFuture in a map then cancel based on the key?

   static ConcurrentMap<String,ScheduledFuture<?>> futures = new ConcurrentHashMap<>();

    public static void start(final String str1, final String str2) {

    String key = str1+str2;
    futures.put(key , syncThreadHandle = svc.scheduleAtFixedRate(new Runnable() {
        @Override
        public void run() {
            System.out.println("First string for this thread str1 " + str1
                    + " Str2 " + str2);
        }

    }, 0, 1, TimeUnit.MINUTES));
}

public static void stop(final String str1, final String str2) {
   futures.get(str1+str2).cancel(true);
}

The key can be either str1 or str2 (or both?).