javaFX : How to periodically load information from db and show it on a Label? - database

Question

I want to execute a method periodically, this method get informations from database it show it into a label, I tried the following code :
Timer timer = new Timer();
timer.scheduleAtFixedRate(new TimerTask() {
#Override
public void run() {
//update information
miseAjour();
}
}, 0, 2000);
when i run the main program, the background service run also normaly but when the informations changes on db i get this exception:
Exception in thread "Timer-0" java.lang.IllegalStateException: Not on FX application thread; currentThread = Timer-0
And this is the code of method miseAjour :
public void miseAjour(){
try {
dbConnection db = new dbConnection();
Connection connect = db.connectiondb();
connect.setAutoCommit(false);
Statement stmt= connect.createStatement();
ResultSet rs = stmt.executeQuery("SELECT count(*) as nbrAderent FROM gss_aderent ");
int nbrAderent = rs.getInt("nbrAderent");
rs.close();
stmt.close();
connect.commit();
connect.close();
main_nbrAdrTot.setText(nbrAderent + "");
} catch (SQLException ex) {
Logger.getLogger(SimpleController.class.getName()).log(Level.SEVERE, null, ex);
}
}

Answer 1

You can Timer for this, but I would recommend to use the JavaFX provided API called as ScheduledService.
ScheduledService is made to execute the same Task at regular intervals and since it creates a Task internally, there are API which help you to bind the value to the UI controls.
ScheduledService<Object> service = new ScheduledService<Object>() {
protected Task<Object> createTask() {
return new Task<Object>() {
protected Object call() {
// Call the method and update the message
updateMessage(miseAjour());
return object; // Useful in case you want to return data, else null
}
};
}
};
service.setPeriod(Duration.seconds(10)); //Runs every 10 seconds
//bind the service message properties to your Label
label.textProperty().bind(service.messageProperty()); // or use your label -> main_nbrAdrTot
Inside the dbcall method miseAjour, return the value that you have fetched and you want to update the label with :
public String miseAjour(){
String nbrAderent = null;
try {
dbConnection db = new dbConnection();
Connection connect = db.connectiondb();
connect.setAutoCommit(false);
Statement stmt= connect.createStatement();
ResultSet rs = stmt.executeQuery("SELECT count(*) as nbrAderent FROM gss_aderent ");
nbrAderent = String.valueOf(rs.getInt("nbrAderent"));
connect.commit();
} catch (SQLException ex) {
Logger.getLogger(SimpleController.class.getName()).log(Level.SEVERE, null, ex);
}
finally {
rs.close();
stmt.close();
connect.close();
}
return nbrAderent;
}

Answer 2

Finnaly i resolved the problem ,here is the code :
public class TimerServiceApp {
public void start() throws Exception {
TimerService service = new TimerService();
service.setPeriod(Duration.seconds(10));
service.setOnSucceeded(new EventHandler<WorkerStateEvent>() {
#Override
public void handle(WorkerStateEvent t) {
main_nbrAdrTot.setText(t.getSource().getMessage());
}
});
service.start();
}
private class TimerService extends ScheduledService<Integer> {
private final StringProperty nbrTotAderent = new SimpleStringProperty();
public final void setTotalAderentNumber(String value ) {
nbrTotAderent.set(value);
}
public String getTotalAderentNumber() throws SQLException {
String nbrAderent = null;
ResultSet rs=null;
Statement stmt=null;
Connection connect=null;
try {
dbConnection db = new dbConnection();
connect = db.connectiondb();
connect.setAutoCommit(false);
stmt= connect.createStatement();
rs = stmt.executeQuery("SELECT count(*) as nbrAderent FROM gss_aderent ");
nbrAderent = String.valueOf(rs.getInt("nbrAderent"));
connect.commit();
} catch (SQLException ex) {
Logger.getLogger(SimpleController.class.getName()).log(Level.SEVERE, null, ex);
}
finally {
rs.close();
stmt.close();
connect.close();
}
System.out.println(" Total aderent number updated to :" + nbrAderent + " Aderents ");
return nbrAderent;
}
protected Task<Integer> createTask() {
return new Task<Integer>() {
protected Integer call() throws SQLException {
nbrTotAderent.setValue(getTotalAderentNumber());
updateMessage(getTotalAderentNumber());
return Integer.parseInt(getTotalAderentNumber());
}
};
}
}
} `
and i called this service by :
TimerServiceApp s = new TimerServiceApp();
s.start();
i dont know if the solution is optimised but it work :) thank you #ItachiUchiha i took the solution from yout answer in the following link