I'm having trouble running JavaFX Program which runs on Java version 1.8. I noticed that even if I can run this program on Intellij IDE, it throws
java.lang.reflect.InvocationTargetException
error when I try running it in command line. There are no errors when I use "javac Main.java" but it throws the error after I compile it then type "java Main.java"
Here are the files
src folder
controller folder
Controller.java
model folder
Database.java
view folder
loginview.fxml
registerview.fxml
mainmenu.fxml
Main.java
Main.java
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
import model.Database;
public class Main extends Application {
#Override
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("view/mainmenu.fxml"));
primaryStage.setTitle("Test Program");
primaryStage.setScene(new Scene(root, 600, 600));
primaryStage.show();
}
public static void main(String[] args) {
Database db = new Database();
db.testmethod();
launch(args);
}
}
Controller.java
package controller;
import javafx.event.ActionEvent;
import javafx.fxml.FXMLLoader;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
import java.io.IOException;
public class Controller {
public void exitProgram() {
System.exit(0);
}
public void openRegister(ActionEvent event) {
Parent root;
try {
root = FXMLLoader.load(getClass().getClassLoader().getResource("view/registerview.fxml"));
javafx.stage.Stage stage = new Stage();
stage.setTitle("Register User");
stage.setScene(new Scene(root, 600, 600));
stage.setResizable(false);
stage.show();
close(event);
} catch (IOException e) {
e.printStackTrace();
}
}
public void openLogin(ActionEvent event) {
Parent root;
try {
root = FXMLLoader.load(getClass().getClassLoader().getResource("view/loginview.fxml"));
javafx.stage.Stage stage = new Stage();
stage.setTitle("Login User");
stage.setScene(new Scene(root, 600, 600));
stage.setResizable(false);
stage.show();
close(event);
} catch (IOException e) {
e.printStackTrace();
}
}
public void close(ActionEvent event) {
((Node) (event.getSource())).getScene().getWindow().hide();
}
}
Database.java
package model;
public class Database {
public void testmethod(){
System.out.println("TEST METHOD");
}
}
loginview.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<Pane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="600.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controller.Controller">
<children>
<Label layoutX="134.0" layoutY="145.0" prefHeight="165.0" prefWidth="332.0" text="LOGIN" />
</children>
</Pane>
mainmenu.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.Pane?>
<Pane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="600.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controller.Controller">
<children>
<Button fx:id="buttonReg" layoutX="32.0" layoutY="60.0" mnemonicParsing="false" onAction="#openRegister" prefHeight="104.0" prefWidth="521.0" text="OPEN REGISTER" />
<Button fx:id="buttonLogin" layoutX="32.0" layoutY="211.0" mnemonicParsing="false" onAction="#openLogin" prefHeight="104.0" prefWidth="521.0" text="OPEN LOGIN" />
<Button fx:id="buttonExit" layoutX="32.0" layoutY="356.0" mnemonicParsing="false" onAction="#exitProgram" prefHeight="104.0" prefWidth="521.0" text="EXIT" />
</children>
</Pane>
registerview.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.Pane?>
<Pane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="600.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controller.Controller">
<children>
<Label layoutX="130.0" layoutY="145.0" text="REGISTER" />
</children>
</Pane>
The error in command line
TEST METHOD
Exception in Application start method
java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
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(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
at com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:917)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$1(LauncherImpl.java:182)
at java.lang.Thread.run(Thread.java:748)
Caused by: javafx.fxml.LoadException:
/C:/Users/Bryan/Desktop/TESTRUN/src/view/mainmenu.fxml:6
at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2601)
at javafx.fxml.FXMLLoader.access$700(FXMLLoader.java:103)
at javafx.fxml.FXMLLoader$ValueElement.processAttribute(FXMLLoader.java:922)
at javafx.fxml.FXMLLoader$InstanceDeclarationElement.processAttribute(FXMLLoader.java:971)
at javafx.fxml.FXMLLoader$Element.processStartElement(FXMLLoader.java:220)
at javafx.fxml.FXMLLoader$ValueElement.processStartElement(FXMLLoader.java:744)
at javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2707)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2527)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
at Main.start(Main.java:13)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$8(LauncherImpl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$7(PlatformImpl.java:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$5(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$6(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$3(WinApplication.java:177)
... 1 more
Caused by: java.lang.ClassNotFoundException: controller.Controller
at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at javafx.fxml.FXMLLoader$ValueElement.processAttribute(FXMLLoader.java:920)
... 22 more
Exception running application Main
I noticed that Database runs before throwing the Error. I don't understand what's the cause of this error
on Main.java,
add
import controller.Controller
Instead of having buttons like "Buttons" try to put them with the class
"JFXButton"
You have this:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.Pane?>
<Pane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="600.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controller.Controller">
<Button fx:id="buttonReg" layoutX="32.0" layoutY="60.0" mnemonicParsing="false" onAction="#openRegister" prefHeight="104.0" prefWidth="521.0" text="OPEN REGISTER" />
<Button fx:id="buttonLogin" layoutX="32.0" layoutY="211.0" mnemonicParsing="false" onAction="#openLogin" prefHeight="104.0" prefWidth="521.0" text="OPEN LOGIN" />
<Button fx:id="buttonExit" layoutX="32.0" layoutY="356.0" mnemonicParsing="false" onAction="#exitProgram" prefHeight="104.0" prefWidth="521.0" text="EXIT" />
</Pane>
Try this:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.layout.Pane?>
<Pane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="600.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controller.Controller">
<JFXButton fx:id="buttonReg" layoutX="32.0" layoutY="60.0" mnemonicParsing="false" onAction="#openRegister" prefHeight="104.0" prefWidth="521.0" text="OPEN REGISTER" />
<JFXButton fx:id="buttonLogin" layoutX="32.0" layoutY="211.0" mnemonicParsing="false" onAction="#openLogin" prefHeight="104.0" prefWidth="521.0" text="OPEN LOGIN" />
<JFXButton fx:id="buttonExit" layoutX="32.0" layoutY="356.0" mnemonicParsing="false" onAction="#exitProgram" prefHeight="104.0" prefWidth="521.0" text="EXIT" />
</Pane>
The InvocationTargetException is occurring because the call to method getResource() – in method openRegister() of class Controller – is returning null. You can check this by simply printing out the value returned by method getResource(), for example
System.out.println(getClass().getClassLoader().getResource("view/registerview.fxml"));
It is returning null because method getResource() builds an absolute path to the file registerview.fxml and then checks to see whether such a file exists. The absolute path that method getResources() builds is not the actual path to the file. Hence you need to change the method argument, i.e. "view/registerview.fxml"
I'm guessing that the below solution is not the only solution, but it worked for me.
In order to prevent getting the InvocationTargetException I did the following.
I put class Main in a package which I named jfxtests.
(It is not clear to me, from your question, whether Main is in a package or not.)
I made the controller folder and the view folder sub-packages of jfxtests.
I call method getClass().getResource() and not getClass().getClassLoader().getResource().
In class Controller, I changed the argument that I pass to method getResource().
The only change I made was to class Controller. Here it is with my changes:
package jfxtests.controller; // changed package
import javafx.event.ActionEvent;
import javafx.fxml.FXMLLoader;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
import java.io.IOException;
public class Controller {
public void exitProgram() {
System.exit(0);
}
public void openRegister(ActionEvent event) {
Parent root = null;
try {
root = FXMLLoader.load(getClass().getResource("/jfxtests/view/registerview.fxml")); // changed this line
javafx.stage.Stage stage = new Stage();
stage.setTitle("Register User");
stage.setScene(new Scene(root, 600, 600));
stage.setResizable(false);
stage.show();
close(event);
} catch (IOException e) {
e.printStackTrace();
}
}
public void openLogin(ActionEvent event) {
Parent root;
try {
root = FXMLLoader.load(getClass().getResource("/jfxtests/view/loginview.fxml")); // changed this line
javafx.stage.Stage stage = new Stage();
stage.setTitle("Login User");
stage.setScene(new Scene(root, 600, 600));
stage.setResizable(false);
stage.show();
close(event);
} catch (IOException e) {
e.printStackTrace();
}
}
public void close(ActionEvent event) {
((Node) (event.getSource())).getScene().getWindow().hide();
}
}
Note that since I changed the package for class Controller, I also had to change the FXML files.
fx:controller="jfxtests.controller.Controller"
Related
When I run the following code in eclipse with java 18 I get an error. Please Help. The fxml is generated using the scene builder.
I read the error, but I don't understand the solution. In Main.fxml he thought everything was fine until line 9.
I used this video as a reference.
https://youtu.be/N3LZM4WFHBY?list=PLZPZq0r_RZOM-8vJA3NQFZB7JroDcMwev
Main.java:
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.stage.Stage;
import javafx.scene.Parent;
import javafx.scene.Scene;
public class Main extends Application {
#Override
public void start(Stage primaryStage) {
try {
Parent root = FXMLLoader.load(getClass().getResource("Main.fxml"));
Scene scene = new Scene(root);
primaryStage.setResizable(false);
primaryStage.setScene(scene);
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
Controller.java:
package application;
import java.awt.event.ActionEvent;
public class Controller {
public void up(ActionEvent e) {
System.out.println("UP");
}
public void down(ActionEvent e) {
System.out.println("DOWN");
}
public void right(ActionEvent e) {
System.out.println("RIGHT");
}
public void left(ActionEvent e) {
System.out.println("LEFT");
}
}
Main.fxml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="Controller">
<children>
<Button layoutX="286.0" layoutY="14.0" mnemonicParsing="false" onAction="#up" text="UP" />
<Button layoutX="536.0" layoutY="188.0" mnemonicParsing="false" onAction="#right" text="RIGHT" />
<Button layoutX="273.0" layoutY="361.0" mnemonicParsing="false" onAction="#down" text="DOWN" />
<Button layoutX="14.0" layoutY="188.0" mnemonicParsing="false" onAction="#left" text="LEFT" />
</children>
</AnchorPane>
Error:
javafx.fxml.LoadException:
/C:/Users/suyak/eclipse-workspace/Message/bin/application/Main.fxml:9
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2707)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader$ValueElement.processAttribute(FXMLLoader.java:933)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader$InstanceDeclarationElement.processAttribute(FXMLLoader.java:981)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader$Element.processStartElement(FXMLLoader.java:230)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader$ValueElement.processStartElement(FXMLLoader.java:755)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2808)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2634)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2548)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3331)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3287)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3255)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3227)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3203)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader.load(FXMLLoader.java:3196)
at FirstJavaFX/application.Main.start(Main.java:14)
at javafx.graphics#18.0.2/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:847)
at javafx.graphics#18.0.2/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:484)
at javafx.graphics#18.0.2/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:457)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:399)
at javafx.graphics#18.0.2/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:456)
at javafx.graphics#18.0.2/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
at javafx.graphics#18.0.2/com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at javafx.graphics#18.0.2/com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(WinApplication.java:184)
at java.base/java.lang.Thread.run(Thread.java:833)
Caused by: java.lang.ClassNotFoundException: Controller
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
at javafx.fxml#18.0.2/javafx.fxml.FXMLLoader$ValueElement.processAttribute(FXMLLoader.java:931)
... 22 more
Slaw posted a comment:
You can solve this either by using fx:controller="application.Controller" (the fully qualified name of your controller class) or, I believe, by adding an <?import application.Controller?> instruction to your FXML file. You also need to change your controller class to import javafx.event.ActionEvent instead of the AWT equivalent (that's not related to your current error, but will prevent a future error from occurring).
Writing fx:controller="application.Controller" fixed it.
Below I have the code to launch my JavaFX GUI for a project I am working on. However when I go to execute the classes, it gets stuck. All it prints is Starting MCPY GUI and just sits there any help?
Launcher class
public class MCPY {
public static void main(String args[]) {
System.out.println("Starting MCPY GUI...");
Main.main(args);
}
}
Main
package com.mcpy.gui;
import java.io.IOException;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class Main extends Application {
#Override
public void start(Stage primaryStage) throws Exception{
FXMLLoader loader = new FXMLLoader(getClass().getResource("styles/Main.fxml"));
Parent root;
try {
root = loader.load();
} catch (IOException ioe) {
// log exception
return;
}
//init the connection to the controller class
MainController MainController = loader.getController();
MainController.setMain(this);
//load the scene
primaryStage.setTitle("Minecraft Launcher Python");
primaryStage.setScene(new Scene(root, 800, 500));
primaryStage.show();
};
public static void main(String[] args) {
launch(args);
}
Main.FXML
<?import java.lang.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.image.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.control.TitledPane?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.image.ImageView?>
<?import javafx.scene.image.Image?>
<?import javafx.scene.control.Button?>
<TitledPane animated="false" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" text="Minecraft Launcher Python Login Screen" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="com.mcpy.gui.MainController">
<content>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0">
<children>
<ImageView fitHeight="135.0" fitWidth="119.0" layoutX="14.0" layoutY="14.0" pickOnBounds="true" preserveRatio="true">
<image>
</image>
</ImageView>
<Button id="play" layoutX="231.0" layoutY="176.0" mnemonicParsing="false" onAction="#playButtonActionEvent" text="Play" />
<Button id="login" layoutX="313.0" layoutY="176.0" mnemonicParsing="false" onAction="#loginButtonEvent" text="Login" />
<Button id="create_account" layoutX="77.0" layoutY="176.0" mnemonicParsing="false" onAction="#create_accountButtonEvent" text="Create Account" />
</children></AnchorPane>
</content>
</TitledPane>
MainController
package com.mcpy.gui;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import com.mcpy.gui.Play;
import com.mcpy.gui.Login;
import com.mcpy.gui.CreateAccount;
/* Logic for the main gui. DO NOT EDIT. */
public class MainController {
#SuppressWarnings("unused")
private Main main;
public void setMain(Main main) {
this.main = main;
}
#FXML
private static Button login;
#FXML
private static Button create_account;
#FXML
private static Button play;
#FXML
public void loginButtonEvent(ActionEvent lbe) {
String[] args = (null);
Login.main(args);
};
#FXML
public void create_accountButtonEvent(ActionEvent cabe) {
String[] args = (null);
CreateAccount.main(args);
};
#FXML
public void playButtonActionEvent(ActionEvent pbae) {
Play.play_mc();
}
}
All of the code is here. The Launcher (MCPY.java) the main gui and its respecitve controller and the stylesheet (Main.java, MainController.java and Main.FXML)
EDIT: I have applied the FXML changes suggested by #naimdjon, however upon clicking the button this error is produced: https://pastebin.com/8EV9wfnm
You have multiple namespace declaration in your xml and imports were missing. Change your fxml to this (removed image for testing), this shows a window:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.TitledPane?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.image.ImageView?>
<?import javafx.scene.image.Image?>
<?import javafx.scene.control.Button?>
<TitledPane fx:controller="com.mcpy.gui.MainController" animated="false"
maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity"
minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0"
text="Minecraft Launcher Python Login Screen"
xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml">
<content>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0">
<children>
<ImageView fitHeight="135.0" fitWidth="119.0" layoutX="14.0" layoutY="14.0" pickOnBounds="true" preserveRatio="true">
<image>
</image>
</ImageView>
<Button id="play" layoutX="231.0" layoutY="176.0" mnemonicParsing="false" text="Play" />
<Button id="login" layoutX="313.0" layoutY="176.0" mnemonicParsing="false" text="Login" />
<Button id="create_account" layoutX="77.0" layoutY="176.0" mnemonicParsing="false" text="Create Account" />
</children></AnchorPane>
</content>
</TitledPane>
UPDATE
Upon clicking on the button, you seem to be calling the launch() method. You can't call launch() method more than once in a Java FX application.
When I start my application my transparent javafx.stage.Stage shows a half transparent image as expected. But after a second stage is loaded the first stage loses its transparency.
The weird thing is that if the second fxml file ("MainScreen.fxml") doesn't contains any components like buttons or text fields, the background stays transparent.
I'm using JavaFX with JavaSE-1.8 in eclipse neon.2 on macOS Sierra.
Main class
package customPackage.main;
import javafx.animation.FadeTransition;
import javafx.application.Application;
import javafx.application.Platform;
import javafx.geometry.Rectangle2D;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.stage.Screen;
import javafx.stage.Stage;
import javafx.stage.StageStyle;
import javafx.util.Duration;
public class Main extends Application implements Runnable {
private Stage primaryStage;
private Stage stage;
private Controller launchController;
#Override
public void start(Stage primaryStage) {
this.primaryStage = primaryStage;
launchController = new Controller("LaunchScreen.fxml");
Scene launchScene = new Scene(launchController);
launchScene.setFill(Color.TRANSPARENT);
primaryStage.initStyle(StageStyle.TRANSPARENT);
primaryStage.setAlwaysOnTop(true);
primaryStage.setResizable(false);
primaryStage.setScene(launchScene);
primaryStage.show();
Thread thread = new Thread(this);
thread.start();
}
#Override
public void run() {
try {
Thread.sleep(3000);
// simulate work
} catch (InterruptedException e) {
e.printStackTrace();
}
Controller controller = new Controller("MainScreen.fxml");
Scene scene = new Scene(controller);
Platform.runLater(new Runnable() {
#Override
public void run() {
stage = new Stage();
stage.initStyle(StageStyle.UNDECORATED);
stage.setResizable(false);
stage.setScene(scene);
stage.show();
}
});
}
}
Controller class
package customPackage.main;
import java.io.IOException;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.control.ProgressBar;
import javafx.scene.layout.AnchorPane;
public class LaunchController extends AnchorPane {
#FXML
private ProgressBar bar;
public LaunchController(String filename) {
FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource(filename));
fxmlLoader.setRoot(this);
fxmlLoader.setController(this);
try {
fxmlLoader.load();
} catch (IOException e) {
e.printStackTrace();
}
}
}
FXML File ("LaunchScreen.fxml")
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.effect.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.image.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.AnchorPane?>
<fx:root fx:id="pane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="326.0" prefWidth="883.0" type="AnchorPane" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
<children>
<ImageView fitHeight="326.0" fitWidth="883.0" layoutX="7.0" layoutY="134.0" pickOnBounds="true" preserveRatio="true" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<image>
<Image url="#http://www.lunapic.com/editor/premade/transparent.gif" />
</image>
</ImageView>
</children>
<cursor>
<Cursor fx:constant="DEFAULT" />
</cursor>
</fx:root>
FXML File ("MainScreen.fxml")
<?xml version="1.0" encoding="UTF-8"?>
<?import java.net.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.image.*?>
<?import javafx.scene.control.*?>
<?import java.lang.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.layout.AnchorPane?>
<fx:root fx:id="pane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="720.0" prefWidth="1280.0" type="AnchorPane" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1">
<children>
<ImageView fitHeight="720.0" fitWidth="1280.0" pickOnBounds="true" preserveRatio="true" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<image>
<Image url="#http://i.telegraph.co.uk/multimedia/archive/03589/Wellcome_Image_Awa_3589699k.jpg" />
</image>
</ImageView>
<HBox spacing="100.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0">
<children>
<Button fx:id="button1" mnemonicParsing="false" onAction="#button1Press" prefHeight="45.0" prefWidth="1000.0" text="Singleplayer" />
<Button fx:id="button2" mnemonicParsing="false" onAction="#button2Press" prefHeight="45.0" prefWidth="1000.0" text="Multiplayer" />
<Button fx:id="button3" mnemonicParsing="false" onAction="#button3Press" prefHeight="45.0" prefWidth="1000.0" text="Settings" />
<Button fx:id="button4" mnemonicParsing="false" onAction="#button4Press" prefHeight="45.0" prefWidth="1000.0" text="Quit" />
</children>
<padding>
<Insets bottom="30.0" left="100.0" right="100.0" top="20.0" />
</padding>
</HBox>
<Region fx:id="region" prefHeight="15.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0" />
</children>
</fx:root>
Solution (solved by James_D)
I added
.root {
-fx-background-color: transparent;
}
to the external style sheet and added stylesheets="#application.css" to the root node in the FXML file.
The default CSS style sheet for JavaFX, modena, applies a non-transparent color to the background of the root node. That's the color you're seeing when you display your main view.
The reason you don't see this in your first screen, or if you remove the buttons from the main screen, is that the default style sheet is only loaded the first time the Control class (or one of its subclasses) is instantiated. This is done to avoid the overhead of CSS processing for applications not needing it.
To fix, either add style="-fx-background-color: transparent;" to the root node in the FXML file, or add the rule
.root {
-fx-background-color: transparent ;
}
to the external style sheet.
This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 6 years ago.
This is my Main Class
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.stage.Stage;
import javafx.scene.Parent;
import javafx.scene.Scene;
public class Main extends Application {
#Override
public void start(Stage primaryStage) {
try {
Parent root = FXMLLoader.load(getClass().getResource("application/anwendung.fxml"));
primaryStage.setTitle("Benutzerverwaltung");
root.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
primaryStage.setScene(new Scene(root));
primaryStage.show();
} catch(Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
This is my Controller class
package application;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.Node;
import javafx.scene.control.Button;
import javafx.scene.input.InputEvent;
import javafx.stage.Stage;
class AnwendungsController {
#FXML
public Button closeButton;
#FXML
public void handleCloseButtonAction(ActionEvent event) {
Stage stage = (Stage) closeButton.getScene().getWindow();
stage.close();
}
}
And this is my fxml file
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.text.Font?>
<AnchorPane prefHeight="140.0" prefWidth="350.0" xmlns="http://javafx.com/javafx/8.0.60" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.AnwendungsController">
<children>
<Button fx:id="closeButton" layoutX="18.0" layoutY="100.0" mnemonicParsing="false" onAction="#handleCloseButtonAction" onMouseClicked="#onMouseClickedCancelBtn" prefHeight="26.0" prefWidth="77.0" text="Abbrechen" />
<Label layoutX="10.0" layoutY="27.0" prefHeight="27.0" prefWidth="342.0" text="Sie können das System nun verwenden" textAlignment="CENTER" textOverrun="CLIP">
<font>
<Font name="System Bold" size="18.0" />
</font>
</Label>
</children>
</AnchorPane>
How can I fix it? I try everything from here JavaFX "Location is required." even though it is in the same package
UPDATE:
java.lang.NullPointerException: Location is required.
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3207)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
at application.Main.start(Main.java:20)
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(Unknown Source)
Two problems exist:
1)The File path
2)The Controller was not set properly
Recommendation:
If you are using SceneBuilder, when you want to see what your controller might look like, you can go to View -> Show Sample Controller Skeleton.
Solution
Main class:
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.stage.Stage;
import javafx.scene.Parent;
import javafx.scene.Scene;
public class Main extends Application {
#Override
public void start(Stage primaryStage) {
try {
System.out.println(getClass().getResource("anwendung.fxml").getPath());
//other solution
//FXMLLoader loader = new FXMLLoader(getClass().getResource("anwendung.fxml"));
//Parent root = loader.load();
//Keep in mind that you are calling a static method
Parent root = FXMLLoader.load(getClass().getResource("anwendung.fxml"));
primaryStage.setTitle("Benutzerverwaltung");
root.getStylesheets().add(getClass().getResource("application.css").toExternalForm());
primaryStage.setScene(new Scene(root));
primaryStage.show();
} catch (Exception e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
launch(args);
}
}
Controller:
package application;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.input.MouseEvent;
public class AnwendungsController {
#FXML
private Button closeButton;
#FXML
void handleCloseButtonAction(ActionEvent event) {
}
#FXML
void onMouseClickedCancelBtn(MouseEvent event) {
}
}
FXML:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.text.Font?>
<AnchorPane prefHeight="140.0" prefWidth="350.0" xmlns="http://javafx.com/javafx/8.0.60" xmlns:fx="http://javafx.com/fxml/1" fx:controller="application.AnwendungsController">
<children>
<Button fx:id="closeButton" layoutX="18.0" layoutY="100.0" mnemonicParsing="false" onAction="#handleCloseButtonAction" onMouseClicked="#onMouseClickedCancelBtn" prefHeight="26.0" prefWidth="77.0" text="Abbrechen" />
<Label layoutX="10.0" layoutY="27.0" prefHeight="27.0" prefWidth="342.0" text="Sie können das Systema nun verwenden" textAlignment="CENTER" textOverrun="CLIP">
<font>
<Font name="System Bold" size="18.0" />
</font>
</Label>
</children>
</AnchorPane>
So I have to build this JavaFX application really fast, my code compiles yet the GUI doesn't start and I get exceptions. The problem starts as soon as the FileChooser code is implemented.
public class Main extends Application {
#FXML // fx:id="openButton"
private Button openButton; // Value injected by FXMLLoader
#Override
public void start(Stage primaryStage) throws Exception{
Parent root = FXMLLoader.load(getClass().getResource("Plot.fxml"));
openButton.setOnAction(new EventHandler<ActionEvent>(){
#Override
public void handle(ActionEvent arg0) {
FileChooser fileChooser = new FileChooser();
FileChooser.ExtensionFilter extFilter = new FileChooser.ExtensionFilter("TXT files (*.txt)", "*.txt");
fileChooser.getExtensionFilters().add(extFilter);
File file = fileChooser.showOpenDialog(primaryStage);
System.out.println(file);
}
});
primaryStage.setTitle("Plotter");
primaryStage.setScene(new Scene(root, 1024 , 768));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
The FXML file is as such:
<BorderPane prefHeight="400.0" prefWidth="723.0" xmlns="http://javafx.com/javafx/null" xmlns:fx="http://javafx.com/fxml/1">
<top>
<HBox alignment="TOP_CENTER" prefHeight="50.0" spacing="10.0" BorderPane.alignment="CENTER">
<children>
<Button fx:id="openButton" mnemonicParsing="false" prefHeight="31.0" prefWidth="150.0" text="Open Dataset" />
<Button mnemonicParsing="false" prefHeight="31.0" prefWidth="150.0" text="Button" />
<Button mnemonicParsing="false" prefHeight="31.0" prefWidth="150.0" text="Button" />
</children>
<padding>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0" />
</padding>
<BorderPane.margin>
<Insets />
</BorderPane.margin>
</HBox>
</top>
</BorderPane>
I am completely novice to JavaFX. Any tips is appreciated. P.S. I am using the Gluon scene builder.
Thanks.
The Exceptions:
Exception in Application start method Exception in thread "main"
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$155(LauncherImpl.java:182)
at java.lang.Thread.run(Thread.java:745) Caused by:
java.lang.NullPointerException at sample.Main.start(Main.java:29) at
com.sun.javafx.application.LauncherImpl.lambda$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
Process finished with exit code 1
Answer is to separate the Controller and Application class, so that you don't end up with two instances of the Application class. Otherwise one instance of the Application class will not have some members initialized and will end up throwing null pointer exceptions.
package plot;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.stage.FileChooser;
import java.io.File;
public class Controller {
#FXML // fx:id="openButton"
private Button openButton; // Value injected by FXMLLoader
#FXML
public void open(ActionEvent e) {
FileChooser fileChooser = new FileChooser();
FileChooser.ExtensionFilter extFilter = new FileChooser.ExtensionFilter("TXT files (*.txt)", "*.txt");
fileChooser.getExtensionFilters().add(extFilter);
File file = fileChooser.showOpenDialog(openButton.getScene().getWindow());
System.out.println(file);
}
}
package plot;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class Main extends Application {
#Override
public void start(Stage stage) throws Exception{
FXMLLoader loader = new FXMLLoader(getClass().getResource("Plot.fxml"));
Parent root = loader.load();
stage.setTitle("Plotter");
stage.setScene(new Scene(root, 1024 , 768));
stage.show();
}
public static void main(String[] args) {
launch(args);
}
}
<?import javafx.scene.layout.BorderPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.control.Button?>
<?import javafx.geometry.Insets?>
<BorderPane prefHeight="400.0" prefWidth="723.0" xmlns="http://javafx.com/javafx/null"
xmlns:fx="http://javafx.com/fxml/1"
fx:controller="plot.Controller"
>
<top>
<HBox alignment="TOP_CENTER" prefHeight="50.0" spacing="10.0" BorderPane.alignment="CENTER">
<children>
<Button fx:id="openButton" mnemonicParsing="false" prefHeight="31.0" prefWidth="150.0" text="Open Dataset" onAction="#open"/>
<Button mnemonicParsing="false" prefHeight="31.0" prefWidth="150.0" text="Button"/>
<Button mnemonicParsing="false" prefHeight="31.0" prefWidth="150.0" text="Button"/>
</children>
<padding>
<Insets bottom="10.0" left="10.0" right="10.0" top="10.0"/>
</padding>
<BorderPane.margin>
<Insets/>
</BorderPane.margin>
</HBox>
</top>
</BorderPane>
See related (I advise the first link be studied to understand why this solution works).
Javafx - Can application class be the controller class
What is a NullPointerException, and how do I fix it?