Rerun JavaFX application - javafx

I'm developing a plugin for IntelliJ. It is a menu that has only one option, and clicking it starts a JavaFX application. The application starts normally, but when I close the application and start again I get the following error:
java.lang.IllegalStateException: Application launch must not be called more than once
It's a simple application, the code is as follows:
This is the code in the menu.
try {
Application.launch(MyApplication.class);
} catch (Exception e) {
e.printStackTrace();
}
This is the JavaFX Application.
public class MyApplication extends Application {
#Override
public void start(Stage primaryStage) throws Exception {
try {
FXMLLoader loader = new FXMLLoader(getClass().getResource("/fxml/main-window.fxml"));
loader.setController(new MainController());
AnchorPane root = loader.load();
Scene scene = new Scene(root, 1000, 600);
primaryStage.setScene(scene);
primaryStage.setMaximized(false);
primaryStage.setResizable(false);
primaryStage.show();
} catch (Exception e) {
e.printStackTrace();
}
}
}
How can I rerun the application? I tried to follow some answers here on the site, but I did not understand them very well, nor could I execute them correctly.

Related

JAVAFX: Get User input using dialog before starting main application window

I have a client application, and I want to get the server address, port, and some other info from the user in order to initialize the controller of the main stage.
Currently my code look like this
public class MemoryGameClient extends Application {
#Override
public void start(Stage mainStage) throws Exception {
FXMLLoader fxml = new FXMLLoader(getClass().getResource("MemoryGameClient.fxml"));
MemoryGameClientController controller = fxml.getController()
Parent root = loader.load();
controller.connect(SERVER_ADDRESS, PORT, GAME_BOARD_SIZE);
Scene scene = new Scene(root);
mainStage.setScene(scene);
mainStage.show()
}
public static void main(String[] args) {
launch(args);
}
}
It works fine using the hardcoded values, but I want to be able to open a DialogPane or something like that to get those values from user before initializing the scene and running the main application logic.
Can I set an empty Scene that launch a dialog and after that quitting and starting the main stage? Can I do that from the controller before mainStage.show()?
(I need the user input not only for connecting the server but also to determine the size of the GridPane in root)

Is it possible to launch a JavaFX application through another JavaFX application?

Can I know why there is an error when I say.
Stage s = new Stage();
new CaeserCipherFX().start(s);
This is my code below. I need to launch another JavaFX Application from this one. Please help. Thank you.
public class Main extends Application
{
String args[];
#Override
public void start(Stage stage) throws Exception
{
// creating types of encryptions (Button)
Button caeserCipher = new Button("1. Caeser Cipher");
Button runningKeyCipher = new Button("2. Running Key Cipher");
Button trithemiusCipher = new Button("3. Trithemius Cipher");
Button vignereCipher = new Button("4. Vignere Cipher");
//setting styles
caeserCipher.setTextFill(Color.BLUE);
runningKeyCipher.setTextFill(Color.BLUE);
trithemiusCipher.setTextFill(Color.BLUE);
vignereCipher.setTextFill(Color.BLUE);
/*need to add more!*/
//setting action listeners
String arr [] = {"CaeserCipher","RunningKeyCipher","TrithemiusCipher","VignereCipher"};
caeserCipher.setOnAction((ActionEvent event)->{
//open caeser cipher
Stage s = new Stage();
new CaeserCipherFX().start(s);
});
runningKeyCipher.setOnAction((ActionEvent event)->{
//open running key cipher
stage.hide();
});
trithemiusCipher.setOnAction((ActionEvent event)->{
//open trithemius cipher
stage.hide();
});
vignereCipher.setOnAction((ActionEvent event)->{
//open vignere cipher
stage.hide();
});
// creating flowpane(FlowPane)
FlowPane menu = new FlowPane();
menu.setHgap(25);
menu.setVgap(25);
menu.setMargin(caeserCipher, new Insets(20, 0, 20, 20));
//list for Flowpane(ObservableList)
ObservableList list = menu.getChildren();
//adding list to flowpane
list.addAll(caeserCipher,runningKeyCipher,trithemiusCipher,vignereCipher);
//scene for stage
Scene scene = new Scene(menu);
stage.setTitle("Main Menu");
stage.setScene(scene);
// stage.initStyle(StageStyle.UTILITY);
stage.setHeight(100);
stage.setWidth(600);
stage.setResizable(false);
// Show the Stage (window)
stage.show();
}
}
And I want to launch the code below:
public class CaeserCipherFX extends Application
{
#Override
public void start(Stage stage) throws Exception
{//some other code
//some other code
}
}
There is a ubiquitous JavaFX main application thread which takes a while to get used to.
Think of it like the front-end thread. Theoretically, you should use that thread to handle UI updates and complex cpu tasks such as looking up something in a BD or figuring out the 100000th decimal of PI should be done in a background thread. If you don't do this, the UI will become unresponsive until the DB data is returned, or that decimal is found.
public class TestClass extends Application {
public static void main(String[] args) {
System.out.println("here");
Application.launch(TestClass.class, args);
System.out.println("this is called once application launch is terminated.");
}
#Override
public void init() throws Exception {
super.init(); //To change body of generated methods, choose Tools | Templates.
System.out.println("message from init");
}
#Override
public void start(Stage primaryStage) throws Exception { // this is abstract.
System.out.println("message from start");
Platform.exit(); // if you remove this line, the application won't exit.
}
}
Since JavaFX comes with some prerequisites, you need to start you rapplication using a front-end. You can work around this, but technically,
public void start(Stage primaryStage)
is what , for all intensive purposes, starts your program.
From here, you can use the primaryStage to control most of your application. It's a good idea to put a .onCloseRequest() on it in which you call Platform.exit();
If you want to have multiple windows in your application, you could use something like
public class TestClass extends Application {
public static void main(String[] args) {
System.out.println("here");
Application.launch(TestClass.class, args);
System.out.println("this is called once application launch is terminated.");
}
#Override
public void init() throws Exception {
super.init(); //To change body of generated methods, choose Tools | Templates.
System.out.println("message from init");
}
#Override
public void start(Stage primaryStage) throws Exception { // this is abstract.
primaryStage.setScene(new Scene(new TextArea("this is the first stage (window)")));
primaryStage.setTitle("stage 1");
primaryStage.show();
primaryStage.setOnCloseRequest((event) -> {
Platform.exit();
});
Stage secondaryStage = new Stage();
secondaryStage.setTitle("stage 2");
TextArea ta2 = new TextArea("this is a different stage.");
Scene scene = new Scene(ta2);
secondaryStage.setScene(scene);
secondaryStage.show();
primaryStage.setX(200);
secondaryStage.setX(200 + primaryStage.getWidth() + 50);
}
}
This is what I assume you want to do. Basically create a new window whenever you press a button. You can create stages like this.
The reason for which you can't do it your way is because you are attempting to start another javafx thread by invoking new CaeserCipherFX which is an application object, not a Stage.
new CaeserCipherFX().start(s); // this can only be called once.
IF you absolutely want to have 2 distinct applications (note: not application windows), then you need to have 2 distinct processes.
Lastly, the primaryStage parameter used in either examples is in the beginning basically a placeholder (as in it's constructed, but there's nothing really in it... like a new String()). You can use different stage objects as your "primary" UI.
Lastly, if depending on the stuff you want to decrypt, you may need to use background threads if you want to keep the UI responsiveness. For this you will need to check out the concurrency part of the javafx tutorial.
Is it possible to launch a JavaFX application through another JavaFX application? Not really.
Alternatively, you can use java.lang.ProcessBuilder
This class essentially sends command lines to your operating system shell.
You can use it to run something like "java -jar XXX\YYY\CaeserCipherFX.jar" whenever you click a button. (you'll have to build a CaeserCypherFX project into a jar file)
This will create a new JVM. This means no memory state sharing. You can handle this through IPC.

In JavaFX using JxBrowser invokeAndWaitFinishLoadingMainFrame() method crashes JVM

I'm experimenting with the JXBrowser Chromium browser engine in JavaFX on Mac OS Sierra. I would like to wait until the URL is fully loaded after I call browser.goBack() or browser.goForward() methods so I can check the Navigation History. The simple app below crashes the JVM but the same code works fine in Java (Swing). The same call in a Java swing app works without any issues. Does anyone have any idea why?
public class JavaFXSample extends Application {
#Override
public void init() throws Exception {
// On Mac OS X Chromium engine must be initialized in non-UI thread.
if (Environment.isMac()) {
BrowserCore.initialize();
}
}
#Override
public void start(final Stage primaryStage) {
Browser browser = new Browser();
BrowserView view = new BrowserView(browser);
Scene scene = new Scene(new BorderPane(view), 700, 500);
primaryStage.setScene(scene);
primaryStage.show();
primaryStage.setOnCloseRequest(new EventHandler<WindowEvent>() {
#Override
public void handle(WindowEvent t) {
Platform.exit();
System.exit(0);
}
});
Browser.invokeAndWaitFinishLoadingMainFrame(browser, new Callback<Browser>
() {
#Override
public void invoke(Browser browser) {
browser.loadURL("http://www.google.com");
}
});
}
public static void main(String[] args) {
launch(args);
}
}
Looks like you've faced a deadlock because you create the Browser instance in heavyweight mode. You can try solving this issue by using the "jxbrowser.ipc.external=true" VM parameter that enables lightweight rendering mode and runs Chromium engine in separate native process to avoid deadlocks in UI thread.

JavaFX java.lang.IllegalStateException: Location is not set

Help! I'm stuck.. I try to run my main javafx app
Here is my codes;
#Override
public void start(Stage primaryStage) throws Exception {
try {
FXMLLoader loader = new FXMLLoader();
loader.setLocation(getClass().getResource("/com/utmkl/fxml/SimulatorDisplay.fxml"));
Parent content = (Parent)loader.load();
primaryStage.setResizable(false);
primaryStage.initStyle(StageStyle.UTILITY);
primaryStage.setScene(new Scene(content));
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
Below is my folder structure:
picture Folder structure
Below is the error
java.lang.IllegalStateException: Location is not set.
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2434)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2409)
at com.utmkl.VMCSManager.start(VMCSManager.java:43)
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)
at java.lang.Thread.run(Thread.java:745)
I've found the answer..
the resource need to be in the same folder structure as main class
Here is my Maven-JavaFX Folder structure
VMCS
- src/main/java
- com.utmkl
VMCSManager.java
- src/main/resources
- com.utmkl.fxml
SimulatorDisplay.fxml
So, the correct code (which success to run)
VMCSManager.java
#Override
public void start(Stage primaryStage) throws Exception {
try {
FXMLLoader loader = new FXMLLoader();
loader.setLocation(getClass().getResource("fxml/SimulatorDisplay.fxml"));
Parent content = loader.load();
Scene scene = new Scene(content);
primaryStage.setResizable(false);
primaryStage.initStyle(StageStyle.UTILITY);
primaryStage.setScene(scene);
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
}
Even though you do set a location with loader.setLocation(getClass().getResource("/com/utmkl/fxml/ControllerDisplay.fxml")); it is likely that the resource URL doesn't actually refer to an existing resource on the classpath.
If you add System.out.println(getClass().getResource("/com/utmkl/fxml/ControllerDisplay.fxml")); to your code I think it will print null as a result.

How to access application from controller in javafx

How can I access javafx Application class from a Controller class? If I go into more specific I need to keep one stage and switch scenes.
You can call the following on an arbitrary node of your scene to get the current stage.
Node.getScene().getWindow()
It will give you an object from type Window. (Stage subclasses Window)
Or you hand over the stage from outside of the controller:
FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource(
"Main.fxml"));
fxmlLoader.setRoot(this);
MainController controller = new MainController()
controller.setStage(stage);
fxmlLoader.setController(controller);
try {
fxmlLoader.load();
} catch (IOException exception) {
throw new RuntimeException(exception);
}

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