Help me with some question about Worker/Service/Task in JavaFx 2

Question

I have read some articles in the forum adout mutithreading in JavaFx2, and now I know if I want to do some long-run jobs, i should use Service/Task.
But my application needs a function like this:
1. here is a long-run job(something like getting data from database or other resources);
2. If I clicked a button, then the job started and get the data.
3. When the job is done, I show the data in the tableview of my JavaFx application.
4. then the job waiting some random time(such as 100 seconds).
5. then the job started again automaticlly.
so, the steps are 2->3->4->5->3->4->5->3->4->5->........
so, the important things is that the job runs many times automaticlly.
I know I should implements the job as a Service or Task in javaFx, But where should I put my "while(true){ job.start();sleep(random_time);}" loop code to make the job start automaticlly after some random sleep time.
I wonder what is the best practice for this use case.
My english is poor, but i hope you can understand what i'm dealing with.
Thank you very much!
Edited by: user9529194 on 2011-12-18 下午8:20

Answer 1

Hi,
Based on the response from John,
I think you can acheive the functionality as below.
// Creating the tableview.
TableView<Person> personTable = new TableView<Person>()
// Instantiating the personlist.
ObservableList<Person> persons = FXCollections.observableArrayList();
// Setting the list to the table.
personTable .setItems(persons)
final Button button = new Button("Refresh");
final Timeline repeatTimeLine = new Timeline(
      new KeyFrame(Duration.seconds(100), new EventHandler<ActionEvent>() {
            @Override
         public void handle(ActionEvent event) {
                // Call the service method to update the list.
                   PersonService.updatepersons(persons );
button.setOnAction(new EventHandler<ActionEvent>() {
     @Override
     public void handle(ActionEvent arg0) {
             repeatTimeLine.setCycleCount(Timeline.INDEFINITE);
             repeatTimeLine.play();
});And in the Service class...
public void updatepersons(final ObservableList<Person> persons){
          final Task<List<Person>> getPersonTask = new Task<List<Person>>() {
          @Override
          protected List<Person> call() throws Exception {
               return getPersonService().getPersons();
     getPersonTask .stateProperty().addListener(new ChangeListener<State>() {
          @Override
          public void changed(ObservableValue<? extends State> arg0, State arg1, State newState) {
               switch (newState) {
               case SUCCEEDED:
                    persons.clear();
                    persons.addAll(getPersonTask .getValue());
                    break;
               case FAILED:
                    break;
     ThreadManager.getInstance().schedule(this.getClass(), getPersonTask );
}I hope this code can give you some idea.
Happy Coding !! :)