Problems with FXMLLoader in javaFX tutorials from Oracle - javafx

Question

Some time ago I started javafx tutorials from Oracle website. During doing this tutorial https://docs.oracle.com/javase/8/javafx/get-started-tutorial/fxml_tutorial.htm I encountered a problem. Here is a code:
1) fxml_example.fxml
<?xml version="1.0" encoding="UTF-8"?>
<?import java.net.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.text.*?>
<GridPane fx:controller="fxmlexample.FXMLExampleController"
xmlns:fx="http://javafx.com/fxml" alignment="center" hgap="10" vgap="10">
<fx:script>
function handleSubmitButtonAction(){
actiontarget.setText("Calling the JavaScript");
}
</fx:script>
<padding>
<Insets top="25" right="25" bottom="10" left="25" />
</padding>
<Text text="Welcome" GridPane.columnIndex="0"
GridPane.columnSpan="2" GridPane.rowIndex="0" />
<Label text="User Name:" GridPane.columnIndex="0"
GridPane.rowIndex="1" />
<TextField GridPane.columnIndex="1" GridPane.rowIndex="1" />
<Label text="Password:" GridPane.columnIndex="0"
GridPane.rowIndex="2" />
<PasswordField fx:id="passwordField"
GridPane.columnIndex="1" GridPane.rowIndex="2" />
<HBox alignment="bottom_right" spacing="10"
GridPane.columnIndex="1" GridPane.rowIndex="4">
<Button text="Button" onAction="#handleSubmitButtonAction" />
</HBox>
<Text fx:id="actiontarget" GridPane.columnIndex="0"
GridPane.columnSpan="2" GridPane.halignment="RIGHT"
GridPane.rowIndex="6" />
</GridPane>
2) FXMLExample.java
package application;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class FXMLExample extends Application{
#Override
public void start(Stage stage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("fxml_example.fxml"));
Scene scene = new Scene(root, 300, 275);
stage.setTitle("FXML Welcome");
stage.setScene(scene);
stage.show();
}
public static void main(String[] args){
launch(args);
}
}
3) FXMLExampleController.java
package application;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.text.Text;
public class FXMLExampleController {
#FXML private Text actiontarget;
#FXML protected void handleSubmitButtonAction(ActionEvent event) {
actiontarget.setText("Sign in button pressed");
}
}
And here is a listing of exceptions:
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$154(LauncherImpl.java:182)
at java.lang.Thread.run(Unknown Source)
Caused by: javafx.fxml.LoadException:
/C:/Users/.../eclipse-workspace/FXMLExample/bin/application /fxml_example.fxml:10
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$ValueElement.processStartElement(FXMLLoader.java:744)
at javafx.fxml.FXMLLoader.processStartElement(FXMLLoader.java:2707)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2527)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097)
at application.FXMLExample.start(FXMLExample.java:12)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$161(Launcher Impl.java:863)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$174(PlatformImpl.jav a:326)
at com.sun.javafx.application.PlatformImpl.lambda$null$172(PlatformImpl.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$173(PlatformImpl.java:294)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
... 1 more
Caused by: java.lang.ClassNotFoundException: fxmlexample.FXMLExampleController
at java.net.URLClassLoader.findClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
at java.lang.ClassLoader.loadClass(Unknown Source)
at javafx.fxml.FXMLLoader$ValueElement.processAttribute(FXMLLoader.java:920)
... 22 more
Exception running application application.FXMLExample
So, is something wrong with FXMLLoader? But what? And how to fix it?

Answer 1

Your FXML sets the fx:controller to fxmlexample.FXMLExampleController, yet your package name is application, so the fx:controller value should be application.FXMLExampleController (or you could change your package name to fxmlexample to match the example code).