Question

I am wanting to execute a task at a regular interval from my JavaFX application. The task pulls data from a remote stream.

While I know I could use a Timer as suggested below:

JavaFX periodic background task

I believe this should be able to be done using the JavaFX Service object. There’s mention in the Javadoc about specifying a custom executor (ScheduledThreadPoolExecutor comes to mind here), but how would one specify the period and delay? Ideally, this would use the Service’s usual start, reset, restart, and state bindings…

public class MyFirstLineService extends Service<String> {
     private StringProperty url = new SimpleStringProperty(this, "url");
     public final void setUrl(String value) { url.set(value); }
     public final String getUrl() { return url.get(); }
     public final StringProperty urlProperty() { return url; }

     public MyFirstLineService() {
         setExecutor(new ScheduledThreadPoolExecutor());
     }

     protected Task createTask() {
         final String _url = getUrl();
         return new Task<String>() {
             protected String call() throws Exception {
                 URL u = new URL(_url);
                 BufferedReader in = new BufferedReader(
                         new InputStreamReader(u.openStream()));
                 String result = in.readLine();
                 in.close();
                 return result;
             }
         };
     }
 }

Answer 1

A ScheduledService was requested in the JavaFX issue tracker – RT18702.

The tracker includes source for a preliminary implementation which has not been incorporated in the 2.2 branch. If needed, you could take a look at that source and see if it helps improve on your solution.