I am very new to JavaFX (and java in general) and I have been trying to transition between scenes from an FXML controller. I have tried to look up multiple solutions online however, none of them seem to work.
My main java code:
package main;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class App extends Application {
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("Login.fxml"));
Scene scene1 = new Scene(root);
primaryStage.setScene(scene1);
primaryStage.setTitle("Login");
primaryStage.show();
}
}
... and my LoginController:
package main;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;
import javafx.scene.control.PasswordField;
import javafx.scene.control.TextField;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class LoginController implements Initializable
{
#FXML
private Label loginLabel;
#FXML
private TextField fieldUsername;
#FXML
private PasswordField fieldPassword;
#FXML
public void loginEvent(ActionEvent event) throws Exception{
//This is where I try to change the scene
if (fieldUsername.getText().equals("admin") && fieldPassword.getText().equals("admin")){
Parent parent = FXMLLoader.load(getClass().getResource("Main.fxml"));
Stage primaryStage = new Stage();
Scene scene = new Scene (parent);
primaryStage.setScene(scene);
primaryStage.setTitle("Main Frame");
primaryStage.show();
}
else {
loginLabel.setText("Incorrect Username or Password");
}
}
#Override
public void initialize(URL arg0, ResourceBundle arg1) {}
}
Here is the Error I get:
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.reflect.misc.Trampoline.invoke(Unknown Source)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.reflect.misc.MethodUtil.invoke(Unknown Source)
... 48 more
Caused by: javafx.fxml.LoadException:
/F:/Programming/JAVA/Eclipse/Password%204/bin/main/Main.fxml:9
at javafx.fxml.FXMLLoader.constructLoadException(Unknown Source)
at javafx.fxml.FXMLLoader.access$700(Unknown Source)
at javafx.fxml.FXMLLoader$ValueElement.processAttribute(Unknown Source)
at javafx.fxml.FXMLLoader$InstanceDeclarationElement.processAttribute(Unknown Source)
at javafx.fxml.FXMLLoader$Element.processStartElement(Unknown Source)
at javafx.fxml.FXMLLoader$ValueElement.processStartElement(Unknown Source)
at javafx.fxml.FXMLLoader.processStartElement(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.load(Unknown Source)
at main.LoginController.loginEvent(LoginController.java:34)
... 57 more
Caused by: java.lang.ClassNotFoundException: main.MainController
at java.net.URLClassLoader$1.run(Unknown Source)
at java.net.URLClassLoader$1.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
... 71 more
My way of changing the scene doesn't work. How would I go about this issue?
Thanks in advance.
What is wrong with your solution
Your getResource argument is wrong - you should not use a file path (e.g. F:/) instead you should use something related to your class path.
You may have other errors, I haven't checked, just wanted to note that obvious one.
How to fix it
Easiest solution is to place the Main.fxml in the same directory as LoginController.java and check that, when you compile the program, Main.fxml has been copied by your build system to the same directory as LoginController.class.
For your lookup just use FXMLLoader.load(getClass().getResource("Main.fxml")); (similarly for your Login.fxml).
Sample code
Here is a sample for switching FXML based scenes (your code could be simpler if you want to replace the scene content as a whole rather than parts of the scene like the sample does).
Related
The file "icon.png" is in the same folder as class. But if i just use (new Image("icon.png")) then it says java.lang.IllegalArgumentException: Invalid URL: Invalid URL or resource not found. But now after adding getClass().getResource... i'm getting this error. Here is my code:
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.stage.Stage;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.image.Image;
public class Main extends Application {
public void start(Stage primaryStage) {
try {
Parent root = FXMLLoader.load(getClass().getResource("NewFile.fxml"));
Scene scene = new Scene(root);
primaryStage.setResizable(false);
scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
primaryStage.setScene(scene);
primaryStage.getIcons().add(new Image(getClass().getResource("icon.png").toExternalForm()));
primaryStage.show();
}
catch(Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
And here is the error:
java.lang.NullPointerException
at application.Main.start(Main.java:19)
at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(Unknown Source)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$11(Unknown Source)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$9(Unknown Source)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(Unknown Source)
at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at javafx.graphics/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(Unknown Source)
at java.base/java.lang.Thread.run(Unknown Source)
Please help me to fix it. Thanks in advance!
NullPointerException error is caused due to location of your image is not in the proper position your refer to something which not exist
you can edit your post to show us your project construction
it should be somthing like that to work !
I want to insert video into javaFX. Insert video from computer - Not from youtube or something.
Play/pause/minimize buttons, borders are not needed.
import java.io.FileNotFoundException;
import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.media.Media;
import javafx.scene.media.MediaPlayer;
import javafx.scene.media.MediaView;
import javafx.stage.Stage;
public class MediaMP4 extends Application {
Stage window;
Scene scene1;
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws FileNotFoundException {
window = primaryStage;
primaryStage.setTitle("Moves");
Media media = new Media ("pr.mp4");
MediaPlayer player = new MediaPlayer (media);
MediaView view = new MediaView (player);
Group full = new Group ();
full.getChildren().addAll(view);
scene1 = new Scene (full,600,600);
primaryStage.setScene(scene1);
window.show();
player.play();
}
}
My pr.mp4 file is inside project, not in package.
Stack trace:
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:389)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:328)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$155(LauncherImpl.java:182)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalArgumentException: uri.getScheme() == null! uri == 'pr.mp4'
at com.sun.media.jfxmedia.locator.Locator.<init>(Locator.java:211)
at javafx.scene.media.Media.<init>(Media.java:393)
at vv.MediaMP4.start(MediaMP4.java:27)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191)
... 1 more
Exception running application vv.MediaMP4
The relevant line in your stack trace is:
Caused by: java.lang.IllegalArgumentException: uri.getScheme() == null! uri == 'pr.mp4'.
You need to specify an URI string with a scheme as a construtor argument, as specified here.
So change your line from this:
Media media = new Media ("pr.mp4");
to something like this:
Media media = new Media("file://c:/myproject/pr.mp4"));
Have a look at this question for more details: How to target a file (a path to it) in Java/JavaFX
I'm getting NullPointerException when using org.controlsfx.control.RangeSlider. Here is the simple code example:
package experimental_main;
import org.controlsfx.control.RangeSlider;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
public class Experimental_start extends Application
{
public static void main(String[] args)
{
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception
{
Button button = new Button("Click me");
RangeSlider rangeSlider = new RangeSlider(0, 10, 2, 4);
BorderPane borderPane = new BorderPane();
borderPane.setCenter(rangeSlider);
borderPane.setTop(button);
Scene scene = new Scene(borderPane, 300, 300);
primaryStage.setScene(scene);
primaryStage.show();
}
}
The exception occurs when pressing Tab while right thumb of RangeSlider is focused or pressing Shift+Tab while its left thumb is focused. These key pressings cause to lose focus from RangeSlider as expected, but this action also causes NullPointerException. Here is exception's stack trace:
Exception in thread "JavaFX Application Thread" java.lang.NullPointerException
at com.sun.javafx.scene.traversal.TraversalEngine.select(Unknown Source)
at impl.org.controlsfx.skin.RangeSliderSkin$5.handle(RangeSliderSkin.java:150)
at impl.org.controlsfx.skin.RangeSliderSkin$5.handle(RangeSliderSkin.java:132)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
at javafx.event.Event.fireEvent(Unknown Source)
at javafx.scene.Scene$KeyHandler.process(Unknown Source)
at javafx.scene.Scene$KeyHandler.access$1800(Unknown Source)
at javafx.scene.Scene.impl_processKeyEvent(Unknown Source)
at javafx.scene.Scene$ScenePeerListener.keyEvent(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$KeyEventNotification.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleKeyEvent$353(Unknown Source)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleKeyEvent(Unknown Source)
at com.sun.glass.ui.View.handleKeyEvent(Unknown Source)
at com.sun.glass.ui.View.notifyKey(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$148(Unknown Source)
at java.lang.Thread.run(Unknown Source)
There is no exception when pressing Tab (or Shift+Tab) with a view to make RangeSlider's thumb focused.
Am I doing something wrong or it's a bug? Is there alternative to RangeSlider class realizations?
This listener of the RangeSliderSkin seems to cause the NPE:
EventHandler<KeyEvent> keyEventHandler = new EventHandler<KeyEvent>() {
#Override public void handle(KeyEvent event) {
if (KeyCode.TAB.equals(event.getCode())) {
if (lowThumb.isFocused()) {
if (event.isShiftDown()) {
lowThumb.setFocus(false);
new ParentTraversalEngine(rangeSlider).select(rangeSlider, Direction.PREVIOUS);
} else {
lowThumb.setFocus(false);
highThumb.setFocus(true);
}
event.consume();
} else if (highThumb.isFocused()) {
if(event.isShiftDown()) {
highThumb.setFocus(false);
lowThumb.setFocus(true);
} else {
highThumb.setFocus(false);
new ParentTraversalEngine(rangeSlider).select(rangeSlider, Direction.NEXT);
}
event.consume();
}
}
}
};
To be more specific, the line new ParentTraversalEngine(rangeSlider).select(rangeSlider, Direction.NEXT);
ParentTraversalEngine is initalized without an Algorithm argument, so calling select(rangeSlider, Direction.NEXT) is causing a NPE, as it is supposed to:
Throws:
java.lang.NullPointerException - if there is no algorithm
javadoc
The bug is fixed beginning from version 8.40.13.
I have written a little Clock Widget extending the Text class of JavaFX. To update the Time I am using a Task that basically sets the text to the current System Time. When I run this application in Eclipse it sometimes throws a NullpointerException in the line I call stage.show().
This is what my widgets sourcecode looks like:
package clock;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;
import javafx.concurrent.Task;
import javafx.scene.text.Font;
import javafx.scene.text.Text;
public class CurrentClockText extends Text {
private final DateTimeFormatter formatter;
public static final int HOUR = 1;
public static final int HOUR_MINUTE = 2;
public static final int HOUR_MINUTE_SECOND = 3;
public static final int HOUR_MINUTE_SECOND_MILLISECOND = 4;
private final long updateInterval;
private final Task<Void> updater = new Task<Void>() {
#Override
protected Void call() throws Exception {
while (true) {
LocalDateTime now = LocalDateTime.now();
String nowTextual = formatter.format(now);
setText(nowTextual);
try {
Thread.sleep(updateInterval);
} catch (InterruptedException ignore) {
}
}
}
};
public CurrentClockText() {
this(HOUR_MINUTE);
}
public CurrentClockText(final int detailLevel) {
String timeFormat = "";
switch (detailLevel) {
case HOUR:
timeFormat = "HH";
updateInterval = 60000;
break;
case HOUR_MINUTE:
timeFormat = "HH:mm";
updateInterval = 15000;
break;
case HOUR_MINUTE_SECOND:
timeFormat = "HH:mm:ss";
updateInterval = 500;
break;
case HOUR_MINUTE_SECOND_MILLISECOND:
updateInterval = 1;
timeFormat = "HH:mm:ss.S";
break;
default:
throw new IllegalArgumentException(
"Unknown detail level for Clock: " + detailLevel);
}
setFont(new Font("Verdana", 28));
formatter = DateTimeFormatter.ofPattern(timeFormat);
Thread updaterThread = new Thread(updater, "CurrentClockText.updaterThread");
updaterThread.setDaemon(true);
updaterThread.start();
}
}
This is the main class:
package clock;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
public class Boot extends Application {
#Override
public void start(Stage stage) throws Exception {
BorderPane pane = new BorderPane();
CurrentClockText clock = new CurrentClockText(4);
pane.setCenter(clock);
Scene scene = new Scene(pane);
stage.setScene(scene);
stage.show();
}
public static void main(String[] args) {
Boot.launch(args);
}
}
And this is the stacktrace:
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplication(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$152(Unknown Source)
at com.sun.javafx.application.LauncherImpl$$Lambda$50/14845382.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.NullPointerException
at com.sun.javafx.text.PrismTextLayout.addTextRun(Unknown Source)
at com.sun.javafx.text.GlyphLayout.addTextRun(Unknown Source)
at com.sun.javafx.text.GlyphLayout.breakRuns(Unknown Source)
at com.sun.javafx.text.PrismTextLayout.buildRuns(Unknown Source)
at com.sun.javafx.text.PrismTextLayout.layout(Unknown Source)
at com.sun.javafx.text.PrismTextLayout.ensureLayout(Unknown Source)
at com.sun.javafx.text.PrismTextLayout.getBounds(Unknown Source)
at javafx.scene.text.Text.getLogicalBounds(Unknown Source)
at javafx.scene.text.Text.impl_computeLayoutBounds(Unknown Source)
at javafx.scene.Node$12.computeBounds(Unknown Source)
at javafx.scene.Node$LazyBoundsProperty.get(Unknown Source)
at javafx.scene.Node$LazyBoundsProperty.get(Unknown Source)
at javafx.scene.Node.getLayoutBounds(Unknown Source)
at javafx.scene.Node.prefWidth(Unknown Source)
at javafx.scene.Node.minWidth(Unknown Source)
at javafx.scene.layout.Region.computeChildPrefAreaWidth(Unknown Source)
at javafx.scene.layout.BorderPane.getAreaWidth(Unknown Source)
at javafx.scene.layout.BorderPane.computePrefWidth(Unknown Source)
at javafx.scene.Parent.prefWidth(Unknown Source)
at javafx.scene.layout.Region.prefWidth(Unknown Source)
at javafx.scene.Scene.getPreferredWidth(Unknown Source)
at javafx.scene.Scene.resizeRootToPreferredSize(Unknown Source)
at javafx.scene.Scene.preferredSize(Unknown Source)
at javafx.scene.Scene.impl_preferredSize(Unknown Source)
at javafx.stage.Window$9.invalidated(Unknown Source)
at javafx.beans.property.BooleanPropertyBase.markInvalid(Unknown Source)
at javafx.beans.property.BooleanPropertyBase.set(Unknown Source)
at javafx.stage.Window.setShowing(Unknown Source)
at javafx.stage.Window.show(Unknown Source)
at javafx.stage.Stage.show(Unknown Source)
at clock.Boot.start(Boot.java:19)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$159(Unknown Source)
at com.sun.javafx.application.LauncherImpl$$Lambda$53/19600960.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$172(Unknown Source)
at com.sun.javafx.application.PlatformImpl$$Lambda$45/18503843.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null$170(Unknown Source)
at com.sun.javafx.application.PlatformImpl$$Lambda$48/27167109.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$171(Unknown Source)
at com.sun.javafx.application.PlatformImpl$$Lambda$47/2180324.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$145(Unknown Source)
at com.sun.glass.ui.win.WinApplication$$Lambda$36/3326003.run(Unknown Source)
... 1 more
Exception running application clock.Boot
As I said this Exception only occurs in some runs and not always. It happens mostly when I change the formatting pattern of detailLevel = 4 but remains for another run after changing it back again. I am guessing this might actually have something to do with Eclipse but I can't debug the code either because the Exception gets thrown in the stage.show call which I absolutely do not understand. What's the cause of this random Exception and how can I fix it?
In JavaFX, as in most other GUI toolkits, there is one specific thread which handles all UI related operations. An application must not update the UI outside of this thread. If the UI needs to be updated from another thread, there are usually APIs available which ensure that code is executed in the context of the UI thread. In case of JavaFX, see the Concurrency in JavaFX Tutorial for more information.
In your case, the simplest solution would be to make sure that your setText() call is executed on the JavaFX application thread, not on the thread associated with your Task:
...
Platform.runLater(() -> setText(nowTextual));
...
There are also other APIs available in JavaFX to do animations, which can be used to call a handler method at specific time intervals - that would remove the Thread.sleep() call from your loop. See Timeline for more information.
I'm currently trying to follow a Javafx Tutorial on the web and I have some issues.
I have a project with 3 different packages.
Fist one is : ch.makery.address, it contains the Main
Second is : ch.makery.model it's empty for the moment
Third is : ch.makery.view it contains 2 different fxml files wich correspond to two different layouts.
Here is the Main code :
`package ch.makery.address;
import java.io.IOException;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
public class MainApp extends Application {
private Stage primaryStage;
private BorderPane rootLayout;
#Override
public void start(Stage primaryStage) {
this.primaryStage = primaryStage;
this.primaryStage.setTitle("AddressApp");
initRootLayout();
showPersonOverview();
}
/**
* Initializes the root layout.
*/
public void initRootLayout() {
try {
// Load root layout from fxml file.
FXMLLoader loader = new FXMLLoader();
loader.setLocation(MainApp.class.getResource("view/RootLayout.fxml"));
rootLayout = (BorderPane) loader.load();
// Show the scene containing the root layout.
Scene scene = new Scene(rootLayout);
primaryStage.setScene(scene);
primaryStage.show();
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Shows the person overview inside the root layout.
*/
public void showPersonOverview() {
try {
// Load person overview.
FXMLLoader loader = new FXMLLoader();
loader.setLocation(MainApp.class.getResource("view/PersonOverview.fxml"));
AnchorPane personOverview = (AnchorPane) loader.load();
// Set person overview into the center of root layout.
rootLayout.setCenter(personOverview);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* Returns the main stage.
* #return
*/
public Stage getPrimaryStage() {
return primaryStage;
}
public static void main(String[] args) {
launch(args);
}}`
And here are the errors that it returns :
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(Unknown Source)
at com.sun.javafx.application.LauncherImpl.launchApplication(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at sun.launcher.LauncherHelper$FXHelper.main(Unknown Source)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(Unknown Source)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$156(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.IllegalStateException: Location is not set.
at javafx.fxml.FXMLLoader.loadImpl(Unknown Source)
at javafx.fxml.FXMLLoader.load(Unknown Source)
at ch.makery.adress.MainApp.initRootLayout(MainApp.java:35)
at ch.makery.adress.MainApp.start(MainApp.java:22)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$163(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$176(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null$174(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$175(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(Unknown Source)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$149(Unknown Source)
... 1 more
Exception running application ch.makery.adress.MainApp
For what I understand of it, it appears to be a problem when locating the fxml files. But I don't understand why.
If anybody can help me on it, it would be perfect
Thanks
(Sorry if there is any mistakes in my English it's not my mother tongue)
If your Main is in ch.makery.address and your fxml in ch.makery.view then this is wrong:
view/RootLayout.fxml
as it tries to load the file from ch.makery.address.view.
Try
../view/RootLayout.fxml
instead. (Same for PersonOverview)
It is the path to the fxml files that is wrong in that tutorial had the same issue. Using the ../ to move up one directory should work to fix paths to the fxml files.