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How can you stop a thread so that the task running on it stops permanentl?

I have a javafx application. I programmed it such that the application starts with a progress bar that runs to completion. On completion, The window closes and a login window opens. After you sign in, the login window closes and the main window opens.
But that is not what is happening in my application.
I made a task that runs the progressbar from 0 - 100 and I made the task to run on a Thread. When the task is completed, the window closes and login window opens.
The problem I am encountering is that when I sign in using the login window, the main window opens but the login window didn't close.
I wrote a method to close the login window when the main window opens, but That didnt work.
Please what am I missing?
This is the task class
public class TaskClass implements Runnable {
#Override
public void run() {
for (int i = 0; i < 100; i++) {
try {
progress.setProgress(i / 100.0);
Thread.sleep(100);
} catch (InterruptedException ex) {
Logger.getLogger(RunningController.class.getName()).log(Level.SEVERE, null, ex);
}
}
Platform.runLater(new Runnable() {
#Override
public void run() {
// this is the method that closes the window on which the progress bar is running
closed(clos);
// this is the method that opens the login
windowloadwindow("/inventory/management/login/InventoryManagementlogin.fxml", "DeMak Inventory");
}
});
}
}
This loads the progress bar on a thread
Thread thread;
#FXML
private JFXProgressBar progress;
#Override
public void initialize(URL url, ResourceBundle rb) {
progress.setProgress(0.0);
Runnable tasks = new TaskClass();
thread = new Thread(tasks);
thread.start();
}
After you must have signed in using the login window, This is meant to happen
loadwindow("/inventory/management/ui/Main/main.fxml", "Deemax Inventory"); // a method that opens the main window
closed(closew); // a method that closes the login window

In order to synchronize Platform.runLater() code and background thread code you could use the CountDownLatch Class as following:
Task<Void> task = new Task<Void>() {
#Override
protected Void call() throws Exception {
CountDownLatch sync = new CountDownLatch(1);
Platform.runLater(()->{
// GUI code
// ...
// end of GUI code
sync.countDown();
});
sync.await(); // This method will wait for sync.countDown() to be executed
// ...
// code here will be executed after GUI code has finished
// ...
return null;
}
};
Thread thread = new Thread(task);
thread.start();
But, instead you can solve your problem much easier like this:
Task<Void> task = new Task<Void>() {
#Override
protected Void call() throws Exception {
for (int i = 0; i < 100; i++) {
final int finalCounter = i;
Platform.runLater(()->{
try {
progress.setProgress(finalCounter / 100.0);
} catch (InterruptedException e) {
Logger.getLogger(RunningController.class.getName()).log(Level.SEVERE, null, ex);
}
});
Thread.sleep(100);
}
return null;
}
#Override
protected void succeeded() {
// code here will be executed after the thread had been completed
Platform.runLater(()->{
new Alert(Alert.AlertType.INFORMATION, "Thread Succeeded!").show();
});
closed(clos); // this is the method that closes the window on which the progress bar is running
loadwindow("/inventory/management/login/InventoryManagementlogin.fxml", "DeMak Inventory"); // this is the method that opens the login window
super.succeeded();
}
#Override
protected void failed() {
Platform.runLater(()->{
new Alert(Alert.AlertType.ERROR, "Thread Failed!").show();
});
super.failed();
}
};
Thread thread = new Thread(task);
thread.start();
This is my closed method
private void closed(Node nor) {
Stage stage = (Stage)nor.getScene().getWindow();
stage.close();
}
This is my node object.... It is a vbox containing an X image
#FXML
private VBox clos;
so I pass the node to the method like this.
closed(clos);

JavaFX Auto Open new Window

I have A.fxml and B.fxml. A runing with Java Application override start method. I want to every 40 min in loop(5 times) { open new stage B.fxml and wait stage.close, if stage close continue loop open new stage B fxml. Loop this five times. I try timer timertask i could not. I try JavaFX Service i could not. I create Mythread extend Thread object. This time i could not control loop for next stage. When for statement start opening 5 stage. But i want to loop wait for currentstage is close then go next loop. This is my fail code;
public class Driver extends Application {
public static Stage stage;
#Override
public void start(Stage primaryStage) throws Exception {
FXMLLoader loader = new FXMLLoader(getClass().getResource(View.SETTINGS));
Parent root = loader.load();
Scene scene = new Scene(root);
stage = primaryStage;
stage.setScene(scene);
stage.setTitle("Info Library");
stage.setResizable(false);
stage.show();
RandomQuestionThread thread = new RandomQuestionThread();
if (DBContext.settings.isAbbreviation() || DBContext.settings.isTranslation()) {
thread.start();
}
}
public static void main(String[] args) throws InterruptedException {
DBContext.settings = DBContext.getInstance().settings().getSettings();
launch(args);
HibernateUtil.getSessionFactory().close();
}
}
public class RandomQuestionThread extends Thread {
Thread randomThread = new Thread(this);
private String fxml;
private static String TITLE;
#Override
public void run() {
while (true) {
try {
Thread.sleep(DBContext.settings.getAutoQuestionTime() * 6000);
} catch (InterruptedException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
for (int i = 0; i<DBContext.settings.getAutoQuestionCount(); i++) {
randomFxml();
Platform.runLater(()->{
Parent root = null;
try {
root = new FXMLLoader(getClass().getResource(fxml)).load();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Stage stage = new Stage();
stage.setScene(new Scene(root));
stage.setTitle(TITLE);
stage.show();
System.out.println(currentThread().getName());
});
}
}
}
private void randomFxml() {
int start = 0;
if (DBContext.settings.isTranslation() && DBContext.settings.isAbbreviation()) {
start = new Random().nextInt(2);
} else if (DBContext.settings.isTranslation()) {
start = 1;
}
switch (start) {
case 0:
fxml = View.ABBREVIATION;
break;
case 1:
fxml = View.TRANSLATION;
break;
default:
break;
}
if (start == 0) {
TITLE = "KISALTMA SORUSU";
} else TITLE = "ÇEVİRİ SORUSU";
}
}
I need to work more Java multi threads. But after fix this problem. Please explain where I'm doing wrong. In loop write console currentThread name console result "Java Apllication Thread". But i set my thread name "MyThread". I'm so confused.My brain gave blue screen error.

You've put your System.out.println(currentThread().getName()) statement into Platform.runLater(), which means that it will be executed on JavaFX Application Thread (see JavaDoc).
Regarding your question about scheduling some task to repeat fixed number of times with predefined rate, this post could help you.

In loop write console currentThread name console result "Java Apllication Thread". But i set my thread name "MyThread". I'm so confused.
Using Platform.runLater you schedule the Runnable to be executed on the javafx application thread instead of the current thread which allows you to modify the UI, but also results in the current thread being the javafx application thread instead of the thread you call Platform.runLater from...
If you want to continue the "loop" after the window has been closed, you should schedule opening the next window after the last one has been closed. Stage.showAndWait() is a convenient way to wait for the stage to be closed.
For scheduling I'd recommend using a ScheduledExecutorService:
private ScheduledExecutorService executor;
#Override
public void stop() throws Exception {
// stop executor to allow the JVM to terminate
executor.shutdownNow();
}
#Override
public void init() throws Exception {
executor = Executors.newSingleThreadScheduledExecutor();
}
#Override
public void start(Stage primaryStage) {
Button btn = new Button("Start");
btn.setOnAction(new EventHandler<ActionEvent>() {
public void handle(ActionEvent event) {
// just display a "empty" scene
Scene scene = new Scene(new Pane(), 100, 100);
Stage stage = new Stage();
stage.setScene(scene);
// schedule showing the stage after 5 sec
executor.schedule(new Runnable() {
private int openCount = 5;
#Override
public void run() {
Platform.runLater(() -> {
stage.showAndWait();
if (--openCount > 0) {
// show again after 5 sec unless the window was already opened 5 times
executor.schedule(this, 5, TimeUnit.SECONDS);
}
});
}
}, 5, TimeUnit.SECONDS);
}
});
StackPane root = new StackPane();
root.getChildren().add(btn);
Scene scene = new Scene(root);
primaryStage.setScene(scene);
primaryStage.show();
}

I fix this. I used Timer and TimeTask in my main controller init method. And its work. But same code in app start method or in mian method stage didnt wait. I used stageshowandwait() method but thread didnt wait. But same code woked in main controller init method. Why i dont know.
Timer timer = new Timer();
TimerTask timerTask = new TimerTask() {
#Override
public void run() {
Platform.runLater(()->{
for (int i = 0; i<4; i++) {
Parent root = null;
try {
root = new FXMLLoader(getClass().getResource(View.ABBREVIATION)).load();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
Stage stage = new Stage();
stage.setScene(new Scene(root));
stage.setTitle("deneme");
stage.showAndWait();
}
});
}
};
timer.schedule(timerTask, 6000);

JavaFX Multithreading Issue [duplicate]

This question already has an answer here:
JavaFx2 IllegalStateException with Label.setText
(1 answer)
Closed 6 years ago.
I'm currently making an application in which we want to use multithreading to display the flashing label "loading" for a certain period of time after logging in, before continuing on to the next page. Here is my current progress:
public class LoadingController implements Initializable {
#FXML
private Label loadingLabel;
boolean ready = false;
public void setReady() {
System.out.println("now I'm ready");
ready = true;
}
public void showLabel() {
this.loadingLabel.setVisible(true);
}
public void hideLabel() {
this.loadingLabel.setVisible(false);
}
public void goToPage2() {
try {
Parent root = FXMLLoader.load(getClass().getResource("Page2.fxml"));
Scene scene = new Scene(root);
Stage stage = Assignment.getStage();
stage.setScene(scene);
} catch (IOException ex) {
Logger.getLogger(LoadingController.class.getName()).log(Level.SEVERE, null, ex);
}
}
/**
* Initializes the controller class.
*/
#Override
public void initialize(URL url, ResourceBundle rb) {
System.out.println("In loading page");
// TODO launch thread
Thread2 thread = new Thread2(this);
thread.start();
}
}
public class Thread2 extends Thread {
private LoadingController con;
public Thread2(LoadingController con) {
this.con = con;
}
public void run() {
System.out.println("Hello from a thread!");
try {
for (int i = 0; i < 20; i++) {
con.hideLabel();
Thread.sleep(100);
con.showLabel();
Thread.sleep(100);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
con.setReady();
}
}
I currently get this error relating to line
Scene scene = new Scene(root);
Exception in thread "Thread-6" java.lang.IllegalStateException: Not on FX application thread.
Would anyone be able to provide some guidance on this issue?
Thank you

The guidance is very simple - read the relevant documentation about JavaFX concurrency.
https://docs.oracle.com/javase/8/javafx/interoperability-tutorial/concurrency.htm
The exception clearly tells you what is wrong. You try to create a new Scene from the wrong thread. SceneGraph manipulations are only allowed from the JavaFX application thread.

Java JProgressBar does not show up by setVisible(true)

I have a method like below.
ProgressWindow is a sub class of JFrame containing JProgressBar.
addProgress() increments a value in the JProgressBar.
If I call this method from a method in another class, a frame of ProgressWindow will show up but not JProgressBar and some JLabels inside the frame. They show up after the last line (System.out.println("finish")).
If I call this method in a main method in the class containing this method, then every component (Bar, labels...) instantly shows up.
What can I do for showing the window correctly?
static void search(){
ProgressWindow window = new ProgressWindow();
window.setVisible(true);
ExecutorService execs = Executors.newFixedThreadPool(Runtime
.getRuntime().availableProcessors());
Collection<Callable<Void>> processes = new LinkedList<>();
for (int i = 0; i < 100; i++) {
processes.add(new Callable<Void>() {
#Override
public Void call() throws Exception {
progressWindow.addProgress(); // increment progress value
return null;
}
});
}
try {
execs.invokeAll(processes);
} catch (Exception e) {
e.printStackTrace();
} finally {
execs.shutdown();
}
System.out.println("finish");

The main problem is you seem to be calling search from the context of the Event Dispatching Thread.
The problem occurs because you are using execs.invokeAll which blocks until all the callables have finished running.
This means that the EDT is unable to process new events in Event Queue, including repaint events, this is why your UI is coming to a stand still...
There are a number of issues you are now going to face...
You should never update/modify a UI component from any thread other than the EDT
You should block the EDT for any reason
You seem to want to know when the search is complete, so you know need some kind of event notification...
The first thing we need is some way to be notified that the search has completed, this means you can no longer rely on search returning when the search is complete...
public interface SearchListener {
public void searchCompleted();
}
Next we need an intermeditate search method that builds the UI and ensure that the search is launched within it's own Thread...
static void search(final SearchListener listener) {
final ProgressWindow window = new ProgressWindow();
window.setVisible(true);
Thread t = new Thread(new Runnable() {
#Override
public void run() {
search(listener, window);
}
});
t.start();
}
Then we need to modify the original search method to utilise the SearchListener interface to provide notification when the search is complete...
static void search(final SearchListener listener, final ProgressWindow window){
ExecutorService execs = Executors.newFixedThreadPool(Runtime
.getRuntime().availableProcessors());
Collection<Callable<Void>> processes = new LinkedList<>();
for (int i = 0; i < 100; i++) {
processes.add(new Callable<Void>() {
#Override
public Void call() throws Exception {
// This method needs to ensure that
// what ever it does to the UI, it is done from within
// the context of the EDT!!
progressWindow.addProgress();
return null;
}
});
}
try {
execs.invokeAll(processes);
} catch (Exception e) {
e.printStackTrace();
} finally {
execs.shutdown();
}
System.out.println("finish");
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
listener.searchCompleted();
}
});
}
Now, without the source code for addProgress, I might be tempted to use
processes.add(new Callable<Void>() {
#Override
public Void call() throws Exception {
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
progressWindow.addProgress();
}
});
return null;
}
});
}
Instead...
Take a look at Concurrency in Swing for more details

Sounds like you what you're wanting to do is invoke the setVisible on the Swing UI thread, you can do this with invokeAndWait or invokeLater.
So something like:
final ProgressWindow window = new ProgressWindow();
SwingUtilities.invokeLater(new Runnable() {
#Override
public void run() {
window.setVisible(true);
}
});

ProgressMonitorDialog - Watching active thread to update monitor

In my GUI I have a PDF file creation operation. The operation can take up to 10-15 seconds to complete. When I start the operation, I attach a listener to it. The listener changes the cursor and disables the GUI, until the operation completes.
I would also like to add a progressbar, so the users will have a idea when it is going to complete.
Created a method startProgressBar() and called it from the start of the operation method.
See Below:
private void startSavePdfOperation() {
startProgressBar();
saveOp = new AplotSaveOperation(appReg.getString("aplot.message.SAVETOPDF"), "PDF", session);
saveOp.addOperationListener(new MyOperationListener(this) {
startProgressBar Method - See Below:
public void startProgressBar() {
Shell shell = new Shell(getShell());
shell.setSize(260, 120);
final ProgressBar bar = new ProgressBar(shell, SWT.SMOOTH);
bar.setBounds (20, 20, 200, 20);
shell.open();
final int maximum = bar.getMaximum();
new Thread(new Runnable() {
public void run() {
for (final int[] i = new int[1]; i[0] <= maximum; i[0]++) {
try {Thread.sleep (100);} catch (Throwable th) {}
if (Display.getDefault().isDisposed()) return;
Display.getDefault().asyncExec(new Runnable() {
public void run() {
if (bar.isDisposed ()) return;
bar.setSelection(i[0]);
}
});
}
}
}).start();
The code above created the ProgressBar. The issue is that the operation would end well before the progressbar indicator was close to ending.
Question: Is this because in the method I am creating a new thread and the indicator is updating according to the new thread and not the operation thread?
Question: Is it possible to create a new thread that watches the GUI thread and updates the progressbar accordingly?
Read a article suggesting using ProgressMonitorDialog with IRunnableWithProgress.
Method startProgressBar using ProgressMonitorDialog - see below:
public void startProgressBar() {
ProgressMonitorDialog dialog = new ProgressMonitorDialog(getShell());
try {
dialog.run(true, true, new IRunnableWithProgress(){
public void run(IProgressMonitor monitor) {
monitor.beginTask("Some nice progress message here ...", 100);
** getThread(); **
monitor.done();
}
});
}
catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void getThread() {
new Thread etc.. etc...
}
It seems that it will have the same issues with threading and updating as the code above.
Question: So now I am thinking can I just add or update the ProgressBar to my existing Listener
OperationListener Code - see below:
public abstract class MyOperationListener implements InterfaceAIFOperationListener {
AplotCreatePDFDialog w = null;
public MyOperationListener(AplotCreatePDFDialog win) {
w = win;
}
public void startOperation(String startMessage) {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_WAIT));
w.recursiveSetEnabled(getShell(), getShell().getEnabled());
w.getShell().setEnabled(!getShell().getEnabled());
}
});
}
public void endOperation() {
try {
endOperationImpl();
}
finally {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_ARROW));
w.recursiveSetEnabled(getShell(), true);
w.getShell().setEnabled(!getShell().getEnabled());
w.close();
}
});
}
}
abstract protected void endOperationImpl();
} // end class MyOperationListener
Thanks for any help you can give me with this.
EDIT
Baz, your answer below is exactly what the question asked, so thank you for answering.
But I am starting to think that what I am trying to do is not possible.
When my operation starts, I wanted the progress bar indicator to start and when my operation ended I wanted the indicator be at the end and the monitor would close.
I thought there might bee a way to use my listener to add the progressbar. Something like the following.
public void startOperation(String startMessage) {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
->monitor.beginTask("Creating PDF File(s)", IProgressMonitor.UNKNOWN);<-
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_WAIT));
w.recursiveSetEnabled(getShell(), getShell().getEnabled());
w.getShell().setEnabled(!getShell().getEnabled());
}
});
}
public void endOperation() {
try {
->monitor.worked(1);<-
endOperationImpl();
}
finally {
Display.getDefault().asyncExec(new Runnable() {
public void run() {
w.getShell().setCursor(new Cursor(Display.getCurrent(), SWT.CURSOR_ARROW));
w.recursiveSetEnabled(getShell(), true);
w.getShell().setEnabled(!getShell().getEnabled());
->monitor.done();<-
w.close();
}
});
}
}
abstract protected void endOperationImpl();
} // end class MyOperationListener
But I am starting to see that the ProgressBar has to have some sort of measurement to display the indicator correctly.
I would be happy if the indicator just went back and forth and the monitor would close at the end of the operation.

Why not use ProgressMonitorDialog?
Here is a related answer from me showing a simple example.
This is what it looks like:
If you are not sure about the workload, use this code:
monitor.beginTask("Copying files", IProgressMonitor.UNKNOWN);
It will show the idle bar while running.