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Executor and Daemon in Java

Asked 2009-10-04T11:14:52.280
11

I have a MyThread object which I instantiate when my app is loaded through the server, I mark it as a Daemon thread and then call start() on it. The thread is meant to sit and wait for information from a queue as long as the application is active. My problem/question is this: Currently MyThread is extending Thread because I mark it as Daemon and I read about how it's more prefferable to implement Runnable and to use Executors. So what I wanted to ask is if MyThread will implement Runnable instead of extending Thread (and of course will be renamed) and I'll use newSingleThreadScheduledExecutor() how, what or maybe where, do I mark something as Daemon. I hope I haven't made a mess of terms, please excuse me if I have as some parts of the multithreading environment are very new to me.

Thanks Ittai

Update: The module I'm referring to in my app is a web-app which has a few threads actually of this sort and what they do have in common is that they all in the ServletContext as a member for various reasons. Currently I extend Thread to WebThread which has the ServletContext as a memebr and all subclasses can utilize this. If I switch over to the Runnable paradigm with the Executor and ThreadFactory than basically I need to have an ugly hybrid of WebRunnable which implements Runnable and has the ServletContext as a public member and have my ThreadFactory implement newThread(WebRunnable arg0) in addition to newThread(Runnable arg0). I'm not sure what's best. Thanks

java multithreading daemon executor
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2 Answers

12

If you're using a scheduled executor, you can provide a ThreadFactory. This is used to create new Threads, and you can modify these (e.g. make them daemon) as you require.

EDIT: To answer your update, your ThreadFactory just needs to implement newThread(Runnable r) since your WebRunnable is a Runnable. So no real extra work.

answered 2009-10-04T11:21:39.970
2

Just to complement with another possible solution for completeness. It may not be as nice though. 

final Executor executor = Executors.newSingleThreadExecutor();
Runtime.getRuntime().addShutdownHook(new Thread() {

    @Override
    public void run() {
        executor.shutdownNow();
    }
});
answered 2012-02-09T16:06:08.163

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