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JavaFX: " Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException" Error on JavaFX

After selecting date on my DatePicker I see those errors:
E:\все jdk\jdk1.8.0_152\bin\java" -Didea.launcher.port=7533 "-Didea.launcher.bin.path=C:\Program Files (x86)\JetBrains\IntelliJ IDEA 2016.3.8\bin" -Dfile.encoding=UTF-8 -classpath "E:\все jdk\jdk1.8.0_152\jre\lib\charsets.jar;E:\все jdk\jdk1.8.0_152\jre\lib\deploy.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\access-bridge-64.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\cldrdata.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\dnsns.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\jaccess.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\jfxrt.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\localedata.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\nashorn.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\sunec.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\sunjce_provider.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\sunmscapi.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\sunpkcs11.jar;E:\все jdk\jdk1.8.0_152\jre\lib\ext\zipfs.jar;E:\все jdk\jdk1.8.0_152\jre\lib\javaws.jar;E:\все jdk\jdk1.8.0_152\jre\lib\jce.jar;E:\все jdk\jdk1.8.0_152\jre\lib\jfr.jar;E:\все jdk\jdk1.8.0_152\jre\lib\jfxswt.jar;E:\все jdk\jdk1.8.0_152\jre\lib\jsse.jar;E:\все jdk\jdk1.8.0_152\jre\lib\management-agent.jar;E:\все jdk\jdk1.8.0_152\jre\lib\plugin.jar;E:\все jdk\jdk1.8.0_152\jre\lib\resources.jar;E:\все jdk\jdk1.8.0_152\jre\lib\rt.jar;C:\Users\ogobe\IdeaProjects\YSK_1\out\production\YSK_1;C:\Program Files (x86)\JetBrains\IntelliJ IDEA 2016.3.8\lib\idea_rt.jar" com.intellij.rt.execution.application.AppMain sample.Main
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8413)
at com.sun.javafx.scene.control.skin.DatePickerSkin.handleControlPropertyChanged(DatePickerSkin.java:147)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase.lambda$registerChangeListener$61(BehaviorSkinBase.java:197)
at com.sun.javafx.scene.control.MultiplePropertyChangeListenerHandler$1.changed(MultiplePropertyChangeListenerHandler.java:55)
at javafx.beans.value.WeakChangeListener.changed(WeakChangeListener.java:89)
at com.sun.javafx.binding.ExpressionHelper$Generic.fireValueChangedEvent(ExpressionHelper.java:361)
at com.sun.javafx.binding.ExpressionHelper.fireValueChangedEvent(ExpressionHelper.java:81)
at javafx.beans.property.ObjectPropertyBase.fireValueChangedEvent(ObjectPropertyBase.java:105)
at javafx.beans.property.ObjectPropertyBase.markInvalid(ObjectPropertyBase.java:112)
at javafx.beans.property.ObjectPropertyBase.set(ObjectPropertyBase.java:146)
at javafx.scene.control.ComboBoxBase.setValue(ComboBoxBase.java:150)
at com.sun.javafx.scene.control.skin.DatePickerContent.selectDayCell(DatePickerContent.java:689)
at com.sun.javafx.scene.control.skin.DatePickerContent.lambda$createDayCells$174(DatePickerContent.java:731)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$ClickGenerator.postProcess(Scene.java:3470)
at javafx.scene.Scene$ClickGenerator.access$8100(Scene.java:3398)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3766)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:394)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$353(GlassViewEventHandler.java:432)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:431)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
... 60 more
Caused by: java.lang.NullPointerException
at sample.Controller.getDate(Controller.java:72)
... 70 more
number of years: 1
number of months: 0
number of days: 0
Process finished with exit code 0
Controller.java:
package sample;
import java.net.URL;
import java.time.LocalDate;
import java.time.Month;
import java.time.format.DateTimeFormatter;
import java.time.temporal.TemporalAccessor;
import java.util.Calendar;
import java.util.Date;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.event.Event;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.ChoiceBox;
import javafx.scene.control.DatePicker;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import java.time.Period;
import javax.swing.*;
public class Controller {
#FXML
private ResourceBundle resources;
#FXML
private URL location;
#FXML
private DatePicker date_1;
#FXML
private DatePicker date_2;
#FXML
private Button buttonAdd;
#FXML
private ChoiceBox<?> choiceBox;
#FXML
private TextField lavozm;
#FXML
private Label year;
#FXML
private Label month;
#FXML
private Label yearOfIIN;
#FXML
private Label monthOfXis;
#FXML
private Label dayOfXis;
public void getDate(ActionEvent event) {
LocalDate dt1 = date_1.getValue();
Calendar c = Calendar.getInstance();
c.set(dt1.getYear(), dt1.getMonthValue(), dt1.getDayOfMonth());
Date date1 = c.getTime();
LocalDate dt2 = date_2.getValue();
Calendar c2 = Calendar.getInstance();
c2.set(dt2.getYear(), dt2.getMonthValue(), dt2.getDayOfMonth());
Date date2 = c.getTime();
Period age = Period.between(dt1, dt2);
int years = age.getYears();
int months = age.getMonths();
int days = age.getDays();
System.out.println("number of years: " + years);
System.out.println("number of months: " + months);
System.out.println("number of days: " + days);
}
#FXML
void initialize() {
}
}
Main.java:
package sample;
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{
Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
primaryStage.setTitle("YSK");
primaryStage.setScene(new Scene(root, 800, 550));
primaryStage.setResizable(false);
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
sample.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.ChoiceBox?>
<?import javafx.scene.control.DatePicker?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.text.Text?>
<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="550.0" prefWidth="829.0" xmlns="javafx/8.0.141" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
<children>
<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="68.0" prefWidth="829.0" style="-fx-background-color: #1d90ed;">
<children>
<TextField layoutX="521.0" layoutY="21.0" prefHeight="16.0" prefWidth="269.0" promptText="Ходим исм шарфи" style="-fx-background-color: #EAFAFA;" />
</children>
</AnchorPane>
<DatePicker fx:id="date_1" layoutX="14.0" layoutY="123.0" onAction="#getDate" prefHeight="27.0" prefWidth="149.0" promptText="Боши" />
<DatePicker fx:id="date_2" layoutX="176.0" layoutY="124.0" onAction="#getDate" prefHeight="27.0" prefWidth="149.0" promptText="Якуни" />
<Button fx:id="buttonAdd" layoutX="387.0" layoutY="172.0" minWidth="26.0" mnemonicParsing="false" prefHeight="17.0" prefWidth="56.0" style="-fx-background-color: #1d90ed;" text="+" />
<ChoiceBox fx:id="choiceBox" layoutX="332.0" layoutY="124.0" prefHeight="26.0" prefWidth="48.0" />
<Text layoutX="28.0" layoutY="438.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Календар хисобида:" />
<Text layoutX="65.0" layoutY="467.0" strokeType="OUTSIDE" strokeWidth="0.0" text="Имтиез блан:" />
<TextField fx:id="lavozm" layoutX="395.0" layoutY="124.0" prefHeight="26.0" prefWidth="185.0" promptText="Лавозм" />
<Text layoutX="624.0" layoutY="143.0" strokeType="OUTSIDE" strokeWidth="0.0" text="йил" />
<Text layoutX="750.0" layoutY="144.0" strokeType="OUTSIDE" strokeWidth="0.0" text="кун" />
<Text layoutX="689.0" layoutY="143.0" strokeType="OUTSIDE" strokeWidth="0.0" text="ой" />
<Label fx:id="year" layoutX="587.0" layoutY="126.0" prefHeight="25.0" prefWidth="28.0" />
<Label fx:id="month" layoutX="654.0" layoutY="127.0" prefHeight="25.0" prefWidth="28.0" />
<Label fx:id="month" layoutX="715.0" layoutY="127.0" prefHeight="25.0" prefWidth="28.0" />
<Text layoutX="187.0" layoutY="437.0" strokeType="OUTSIDE" strokeWidth="0.0" text="йил" />
<Text layoutX="313.0" layoutY="438.0" strokeType="OUTSIDE" strokeWidth="0.0" text="кун" />
<Text layoutX="252.0" layoutY="437.0" strokeType="OUTSIDE" strokeWidth="0.0" text="ой" />
<Label fx:id="year" layoutX="150.0" layoutY="420.0" prefHeight="25.0" prefWidth="28.0" />
<Label fx:id="month" layoutX="217.0" layoutY="421.0" prefHeight="25.0" prefWidth="28.0" />
<Label fx:id="month" layoutX="278.0" layoutY="421.0" prefHeight="25.0" prefWidth="28.0" />
<Text layoutX="191.0" layoutY="466.0" strokeType="OUTSIDE" strokeWidth="0.0" text="йил" />
<Text layoutX="317.0" layoutY="467.0" strokeType="OUTSIDE" strokeWidth="0.0" text="кун" />
<Text layoutX="256.0" layoutY="466.0" strokeType="OUTSIDE" strokeWidth="0.0" text="ой" />
<Label fx:id="yearOfIIN" layoutX="154.0" layoutY="449.0" prefHeight="25.0" prefWidth="28.0" />
<Label fx:id="monthOfXis" layoutX="221.0" layoutY="450.0" prefHeight="25.0" prefWidth="28.0" />
<Label fx:id="dayOfXis" layoutX="282.0" layoutY="450.0" prefHeight="25.0" prefWidth="28.0" />
</children>
</AnchorPane>

What is going wrong
dt2 is null, which makes sense because the getDate method in invoked as the onAction handler referenced in fxml for both date_1 and date_2 date pickers.
Whichever one you use to pick a date first, the other will have a null value for the picked date because you can only pick one date at a time.
How to fix it
If either date_1.getValue() or date_2.getValue() is null, the getDate method should be changed to exit (via return).
The method appears to be calculating the period between the two dates (which doesn't make sense for a null date).
Once the user has picked both dates, the call would go through and the period would be calculated correctly.
At the beginning of getDate(), write:
if (date_1.getValue() == null || date_2.getValue() == null) {
System.out.println(“Both dates not yet chosen, will not calculate period”);
return;
}

JavaFX error: Event Handler is not in the namespace

I am creating a JavaFX application. I can start the application and login but when I try to access the Customers Scene, I get the following error:
(Sorry in advance for all the code & errors; didn't want to leave anything out)
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8411)
at javafx.scene.control.Button.fire(Button.java:185)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:394)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:295)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$353(GlassViewEventHandler.java:432)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:431)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$147(WinApplication.java:177)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
... 48 more
Caused by: javafx.fxml.LoadException: Error resolving onAction='#deleteCustomerButtonPushed', either the event handler is not in the Namespace or there is an error in the script.
file:/C:/Users/limpFish/Documents/repositories/c195-java-2/C195/dist/run642260308/C195.jar!/c195/CustomersScene.fxml:27
at javafx.fxml.FXMLLoader.constructLoadException(FXMLLoader.java:2597)
at javafx.fxml.FXMLLoader.access$100(FXMLLoader.java:103)
at javafx.fxml.FXMLLoader$Element.processEventHandlerAttributes(FXMLLoader.java:610)
at javafx.fxml.FXMLLoader$ValueElement.processEndElement(FXMLLoader.java:770)
at javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2823)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2532)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:2409)
at c195.MainSceneController.customersButtonPushed(MainSceneController.java:43)
... 58 more
Here is CustomersScene.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TableColumn?>
<?import javafx.scene.control.TableView?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>
<?import javafx.scene.text.Font?>
<AnchorPane id="AnchorPane" prefHeight="591.0" prefWidth="475.0" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="c195.CustomersSceneController">
<children>
<VBox layoutY="51.0" prefHeight="541.0" prefWidth="500.0">
<children>
<TableView fx:id="customerTableView" prefHeight="470.0" prefWidth="500.0">
<columns>
<TableColumn fx:id="customerTableNameTableColumn" prefWidth="75.0" text="Name" />
<TableColumn fx:id="customerTableAddressTableColumn" prefWidth="302.0" text="Address" />
<TableColumn fx:id="customerTablePhoneNumberTableColumn" minWidth="0.0" prefWidth="122.0" text="Phone Number" />
</columns>
</TableView>
<HBox alignment="CENTER" prefHeight="100.0" prefWidth="200.0" spacing="100.0">
<children>
<Button fx:id="addCustomerButton" mnemonicParsing="false" onAction="#addCustomerButtonPushed" prefHeight="30.0" prefWidth="60.0" text="Add" />
<Button fx:id="modifyCustomerButton" mnemonicParsing="false" onAction="#modifyCustomerButtonPushed" prefHeight="30.0" prefWidth="60.0" text="Modify" />
<Button fx:id="deleteCustomerButton" mnemonicParsing="false" onAction="#deleteCustomerButtonPushed" prefHeight="30.0" prefWidth="60.0" text="Delete" />
</children>
</HBox>
<HBox alignment="CENTER" prefHeight="100.0" prefWidth="200.0" spacing="260.0">
<children>
<Button fx:id="returnButton" mnemonicParsing="false" onAction="#returnButtonPushed" prefHeight="30.0" prefWidth="60.0" text="Return" />
<Button fx:id="quitButton" mnemonicParsing="false" onAction="#quitButtonPushed" prefHeight="30.0" prefWidth="60.0" text="Quit" />
</children>
</HBox>
</children>
</VBox>
<Label layoutX="19.0" layoutY="14.0" prefHeight="30.0" prefWidth="91.0" text="Customers">
<font>
<Font size="18.0" />
</font>
</Label>
</children>
</AnchorPane>
Below is my controller class (in progress):
package c195;
import java.io.IOException;
import java.net.URL;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ResourceBundle;
import java.util.logging.Level;
import java.util.logging.Logger;
import javafx.application.Platform;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Alert;
import javafx.scene.control.Button;
import javafx.scene.control.ButtonType;
import javafx.scene.control.TableColumn;
import javafx.scene.control.TableView;
import javafx.scene.control.cell.PropertyValueFactory;
import javafx.stage.Stage;
public class CustomersSceneController implements Initializable {
#FXML private TableView<Customer> customerTableView;
#FXML private TableColumn<Customer, String> customerTableNameTableColumn;
#FXML private TableColumn<Customer, String> customerTableAddressTableColumn;
#FXML private TableColumn<Customer, String> customerTablePhoneNumberTableColumn;
#FXML private Button addCustomerButton;
#FXML private Button modifyCustomerButton;
#FXML private Button deleteCustomerButton;
#FXML private Button returnButton;
#FXML private Button quitButton;
#FXML private void addCustomerButtonPushed(ActionEvent event) throws IOException
{
FXMLLoader loader = new FXMLLoader();
loader.setLocation(getClass().getResource("AddCustomerScene.fxml"));
Parent addCustomerSceneParent = loader.load();
Scene addCustomerSceneScene = new Scene(addCustomerSceneParent);
Stage window = (Stage) ((Node)event.getSource()).getScene().getWindow();
window.setScene(addCustomerSceneScene);
window.show();
}
#FXML private void modifyCustomerButtonPushed(ActionEvent event) throws IOException
{
// to do
}
#FXML private void deleteCustomerButtonPushed(Customer customer) throws SQLException
{
try
{
PreparedStatement sql = DatabaseUtils.getDBConnection().prepareStatement("Delete customer.*, address.* from customer inner join address on customer.addressId = address.addressId where customer.customerId = ?");
sql.setString(1, Integer.toString(customer.getCustomerId()));
sql.executeUpdate();
}
catch (SQLException e)
{
e.printStackTrace();
}
}
#FXML private void returnButtonPushed(ActionEvent event) throws IOException
{
FXMLLoader loader = new FXMLLoader();
loader.setLocation(getClass().getResource("MainScene.fxml"));
Parent mainSceneParent = loader.load();
Scene mainSceneScene = new Scene(mainSceneParent);
Stage window = (Stage) ((Node)event.getSource()).getScene().getWindow();
window.setScene(mainSceneScene);
window.show();
}
#FXML private void quitButtonPushed(ActionEvent event) throws IOException
{
Alert alert = new Alert(Alert.AlertType.CONFIRMATION,
"Are you sure you want to quit?",
ButtonType.YES,
ButtonType.NO,
ButtonType.CANCEL);
alert.setHeaderText("Quit Confirmation");
alert.showAndWait()
.filter(response -> response == ButtonType.YES)
.ifPresent(response -> {
Platform.exit();
System.exit(0);
});
}
public ObservableList<Customer> updateCustomerTableView() throws SQLException
{
String customerId;
String name;
String address;
String address2;
String city;
String country;
String postalCode;
String totalAddress;
String phone;
ObservableList<Customer> customers = FXCollections.observableArrayList();
try
{
PreparedStatement sql = DatabaseUtils.getDBConnection().prepareStatement("Select customer.customerId, customer.customerName, address.address, address.address2, address.phone, city.city, country.country" +
"from customer" +
"inner join address on customer.addressId = address.addressId" +
"inner join city on address.cityId = city.cityId" +
"inner join country on city.countryId = country.countryId;");
ResultSet result = sql.executeQuery();
while (result.next())
{
customerId = result.getString("customer.customerId");
name = result.getString("custumer.customerName");
address = result.getString("address.address");
address2 = result.getString("address.address2");
city = result.getString("city.city");
country = result.getString("country.country");
postalCode = result.getString("address.postalCode");
phone = result.getString("address.phone");
Customer customer = new Customer(Integer.parseInt(customerId),
name,
address,
address2,
city,
country,
postalCode,
phone);
customers.add(customer);
}
}
catch (SQLException e)
{
e.printStackTrace();
}
return customers;
}
/**
* Initializes the controller class.
*/
#Override
public void initialize(URL url, ResourceBundle rb) {
customerTableNameTableColumn.setCellValueFactory(new PropertyValueFactory<Customer, String>("name"));
customerTableAddressTableColumn.setCellValueFactory(new PropertyValueFactory<Customer, String>("totalAddress"));
customerTablePhoneNumberTableColumn.setCellValueFactory(new PropertyValueFactory<Customer, String>("phone"));
try {
updateCustomerTableView();
} catch (SQLException ex) {
Logger.getLogger(CustomersSceneController.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
The error says that it cannot find the event handler. I don't know why though because I have attached #FXML to the function. I also tried making the function public (both of these are still suggested by the fxml document which shows an error at line 27--> #deleteCustomerButtonPushed)
I have checked all import statements to ensure that the JavaFX version is used.

The InvocationTargetException you get means that the system was trying to find a particular method but was unable to find a suitable candidate. As the error puts it: "the event handler is not in the Namespace".
The problem comes from the signature of your method:
#FXML private void deleteCustomerButtonPushed(Customer customer) {
//...
}
The argument should be a ActionEvent like your other methods, not a Customer.
#FXML private void deleteCustomerButtonPushed(ActionEvent e) {
//...
}

It can be caused from also
using
import java.awt.event.ActionEvent;
instead of
import javafx.event.ActionEvent;

The reason I got this error was I missed the #FXML from the method declaration
it was like this
private void onCheckboxToggle(ActionEvent event) {
Added #FXML
#FXML
private void onCheckboxToggle(ActionEvent event) {
My custom component (nothing speacial):
<CheckBox fx:id="completed" onAction="#onCheckboxToggle" />

JavaFX: Changing Stage

Why doesn't this work? I'm trying to change stage from login screen to sample screen. Getting an error when trying to use ActionEvent connected to Submit button.
Caused by: java.lang.NullPointerException: Location is required.
Main:
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 {
Stage stage;
public static void main(String[] args) {
launch(args);
}
#Override
public void start(Stage primaryStage) throws Exception{
stage = primaryStage;
Parent root = FXMLLoader.load(getClass().getResource("fxml/login.fxml"));
stage.setTitle("Delos");
Scene scene = new Scene(root, 300, 250);
stage.setScene(scene);
stage.show();
}
}
Controller:
package controllers;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Node;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.TextField;
import javafx.stage.Stage;
import java.io.IOException;
import java.net.URL;
import java.util.ResourceBundle;
public class Controller implements Initializable{
//#FXML private TextField username;
#FXML
private void handleLogin(javafx.event.ActionEvent event) throws IOException {
Parent blah = FXMLLoader.load(getClass().getResource("fxml/sample.fxml"));
Scene scene = new Scene(blah);
Stage appStage = (Stage) ((Node) event.getSource()).getScene().getWindow();
appStage.setScene(scene);
appStage.show();
}
/**public void handleLogin(ActionEvent actionEvent) {
System.out.printf("You are logged in %s! %n", username.getText());
}*/
#Override
public void initialize(URL location, ResourceBundle resources) {
}
}
Login.fxml:
<?import javafx.geometry.Insets?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.text.Text?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.Pane?>
<GridPane fx:controller="controllers.Controller"
stylesheets="/css/login.css"
xmlns:fx="http://javafx.com/fxml">
<children>
<Text text="Sign In"
styleClass="title"
GridPane.rowIndex="0"
GridPane.columnSpan="2"
GridPane.halignment="CENTER"/>
<Label text="Username:"
GridPane.rowIndex="1"
GridPane.columnIndex="0"/>
<TextField fx:id="username"
GridPane.rowIndex="1"
GridPane.columnIndex="1"/>
<Label text="Password:"
GridPane.rowIndex="2"
GridPane.columnIndex="0"/>
<TextField fx:id="password"
GridPane.rowIndex="2"
GridPane.columnIndex="1"/>
<Pane GridPane.rowIndex="3">
<children>
<Button text="Login"
onAction="#handleLogin"
GridPane.rowIndex="3"
GridPane.columnIndex="1"
GridPane.halignment="LEFT"/>
</children>
</Pane>
</children>
</GridPane>
sampleController:
package controllers;
/**
* Created by Basse on 22.11.2016.
*/
import javafx.fxml.Initializable;
import java.net.URL;
import java.util.ResourceBundle;
public class sampleController implements Initializable {
#Override
public void initialize(URL location, ResourceBundle resources) {
System.out.println("View is now loaded!");
}
}
Sample.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<VBox prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml"
fx:controller="controllers.sampleController">
<Label text="I love bacon"/>
<Button text="Submit"/>
</VBox>
Edit:
/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/bin/java -Didea.launcher.port=7537 "-Didea.launcher.bin.path=/Applications/IntelliJ IDEA.app/Contents/bin" -Dfile.encoding=UTF-8 -classpath "/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/charsets.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/deploy.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/cldrdata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/dnsns.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/jaccess.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/jfxrt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/localedata.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/nashorn.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/sunec.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/sunjce_provider.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/sunpkcs11.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/ext/zipfs.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/javaws.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/jce.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/jfr.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/jfxswt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/jsse.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/management-agent.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/plugin.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/resources.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/jre/lib/rt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/ant-javafx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/dt.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/javafx-mx.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/jconsole.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/packager.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/sa-jdi.jar:/Library/Java/JavaVirtualMachines/jdk1.8.0_101.jdk/Contents/Home/lib/tools.jar:/Users/Basse/IdeaProjects/Delos/out/production/Delos:/Applications/IntelliJ IDEA.app/Contents/lib/idea_rt.jar" com.intellij.rt.execution.application.AppMain Main
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8411)
at javafx.scene.control.Button.fire(Button.java:185)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:380)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:294)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$354(GlassViewEventHandler.java:416)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:415)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1769)
... 45 more
Caused by: 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 controllers.Controller.handleLogin(Controller.java:24)
... 55 more

JavaFX Starter: Modifying Label Text on other window from Main Window

I'm a new javaFx with Scenebuilder and MVC starter.
I have a problem as below:
I tried to make a main window to alert a new window. And I tried to midified the label text in that alert window. But I cannot do that. And I got this error:
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1774)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1657)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Node.fireEvent(Node.java:8411)
at javafx.scene.control.Button.fire(Button.java:185)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:198)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3757)
at javafx.scene.Scene$MouseHandler.access$1500(Scene.java:3485)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1762)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2494)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:352)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:275)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$355(GlassViewEventHandler.java:388)
at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(QuantumToolkit.java:389)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:387)
at com.sun.glass.ui.View.handleMouseEvent(View.java:555)
at com.sun.glass.ui.View.notifyMouse(View.java:937)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.lambda$null$149(WinApplication.java:191)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:497)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1771)
... 48 more
Caused by: java.lang.NullPointerException
at controller.AlertController.setAlertLabel(AlertController.java:36)
at controller.MainController.onMainButtonClicked(MainController.java:24)
... 58 more
I have a main window with maincontroller, alertController and main.fxml and alert.fxml as below:
Main:
package app;
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{
Parent root = FXMLLoader.load(getClass().getResource("../view/Main.fxml"));
primaryStage.setTitle("Hello World");
primaryStage.setScene(new Scene(root));
primaryStage.show();
}
public static void main(String[] args) {
launch(args);
}
}
Main Controller:
package controller;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
public class MainController {
AlertController alertController = new AlertController();
#FXML
public Label mainLabel;
#FXML
public TextField mainTextField;
#FXML
public Button mainButton;
#FXML
public void onMainButtonClicked() {
alertController.displayAlert();
alertController.setAlertLabel("Hello from MainController!");
}
}
Main.fxml:
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.control.TextField?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.VBox?>
<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8.0.60" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controller.MainController">
<children>
<VBox prefHeight="400.0" prefWidth="600.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<children>
<HBox alignment="CENTER" prefHeight="154.0" prefWidth="600.0">
<children>
<Label fx:id="mainLabel" alignment="CENTER" contentDisplay="TOP" prefHeight="31.0" prefWidth="115.0" text="Main Text" />
</children>
</HBox>
<HBox alignment="CENTER" centerShape="false" layoutX="10.0" layoutY="10.0">
<children>
<TextField fx:id="mainTextField" alignment="TOP_LEFT" prefHeight="25.0" prefWidth="331.0" />
</children>
</HBox>
<HBox alignment="CENTER" layoutX="10.0" layoutY="10.0" prefHeight="100.0" prefWidth="200.0">
<children>
<Button fx:id="mainButton" mnemonicParsing="false" onAction="#onMainButtonClicked" text="Display Alert && Set Message Text" />
</children>
</HBox>
</children>
</VBox>
</children>
</AnchorPane>
AlertController:
package controller;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.stage.Stage;
import java.io.IOException;
public class AlertController {
Stage window;
#FXML
public Label alertLabel;
#FXML
Button alertButton;
public void displayAlert() {
try {
window = new Stage();
Parent root = FXMLLoader.load(getClass().getResource("../view/Alert.fxml"));
Scene scene = new Scene(root);
window.setScene(scene);
window.setTitle("Alert");
window.show();
} catch (IOException e) {
e.printStackTrace();
}
}
public void setAlertLabel(String str) {
alertLabel.setText(str);
}
#FXML
public void onAlertButtonClicked() {
window.close();
}
}
And Alert.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.layout.HBox?>
<?import javafx.scene.layout.VBox?>
<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="210.0" prefWidth="380.0" xmlns="http://javafx.com/javafx/8.0.60" xmlns:fx="http://javafx.com/fxml/1" fx:controller="controller.AlertController">
<children>
<VBox prefHeight="210.0" prefWidth="380.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<children>
<HBox alignment="BOTTOM_CENTER" prefHeight="100.0" prefWidth="200.0">
<children>
<Label fx:id="alertLabel" text="Alert Message" />
</children>
</HBox>
<HBox alignment="CENTER" prefHeight="100.0" prefWidth="200.0">
<children>
<Button fx:id="alertButton" mnemonicParsing="false" onAction="#onAlertButtonClicked" text="Close" />
</children>
</HBox>
</children>
</VBox>
</children>
</AnchorPane>
Please kindly help me solve this problems and explain me why this doesn't work. Thank you for you suggestions.

There are two instances of AlertController: the one you create in MainController with
AlertController alertController = new AlertController();
and the one that is created by the FXMLLoader when you load Alert.fxml in displayAlert().
The #FXML-annotated fields are initialized by the FXMLLoader on the instance it creates. However, you are calling setAlertLabel(...) on an instance of AlertController that was not created by the FXMLLoader. So when you call
alertController.setAlertLabel("Hello from MainController!");
the alertLabel belonging to alertController has not been initialized, and you get a null pointer exception.
Simple Solution
The easiest fix is to load Alert.fxml in MainController, and retrieve the correct controller instance:
public class MainController {
#FXML
public Label mainLabel;
#FXML
public TextField mainTextField;
#FXML
public Button mainButton;
#FXML
public void onMainButtonClicked() {
FXMLLoader loader = new FXMLLoader(getClass().getResource("../view/Alert.fxml"));
Parent root = loader.load();
AlertController alertController = loader.getController();
alertController.setAlertLabel("Hello from MainController!");
Scene scene = new Scene(root);
window.setScene(scene);
window.setTitle("Alert");
window.show();
}
}
and remove the displayAlert() method from AlertController.
Custom Component Solution
An alternative, which is structurally a bit closer to your original, is to replace the AlertController with a custom component.
Alert.fxml (note the change to the root element, and that fx:controller has been removed):
<?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.layout.HBox?>
<?import javafx.scene.layout.VBox?>
<fx:root type="AnchorPane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="210.0" prefWidth="380.0" xmlns="http://javafx.com/javafx/8.0.60" xmlns:fx="http://javafx.com/fxml/1" >
<children>
<VBox prefHeight="210.0" prefWidth="380.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
<children>
<HBox alignment="BOTTOM_CENTER" prefHeight="100.0" prefWidth="200.0">
<children>
<Label fx:id="alertLabel" text="Alert Message" />
</children>
</HBox>
<HBox alignment="CENTER" prefHeight="100.0" prefWidth="200.0">
<children>
<Button fx:id="alertButton" mnemonicParsing="false" onAction="#onAlertButtonClicked" text="Close" />
</children>
</HBox>
</children>
</VBox>
</children>
</fx:root>
AlertController.java:
package controller;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.stage.Stage;
import java.io.IOException;
public class AlertController extends AnchorPane {
Stage window;
#FXML
public Label alertLabel;
#FXML
Button alertButton;
public AlertController() {
window = new Stage();
try {
FXMLLoader loader = new FXMLLoader(getClass().getResource("../view/Alert.fxml"));
loader.setController(this);
loader.setRoot(this);
loader.load();
Scene scene = new Scene(this);
window.setScene(scene);
window.setTitle("Alert");
} catch (IOException e) {
e.printStackTrace();
}
}
public void displayAlert() {
window.show();
}
public void setAlertLabel(String str) {
alertLabel.setText(str);
}
#FXML
public void onAlertButtonClicked() {
window.close();
}
}
and now your main controller can look like this:
package controller;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
public class MainController {
AlertController alertController = new AlertController();
#FXML
public Label mainLabel;
#FXML
public TextField mainTextField;
#FXML
public Button mainButton;
#FXML
public void onMainButtonClicked() {
alertController.displayAlert();
alertController.setAlertLabel("Hello from MainController!");
}
}

java.lang.reflect.InvocationTargetException When get value from TextField - Javafx

I am new to Javafx. I am learning Javafx by developing a simple application. I am trying go get value from TextField in javaFXML. I got java.lang.reflect.InvocationTargetException.
Javafx File.
public class Manoj extends Application {
#Override
public void start(Stage stage) throws Exception {
Parent root = FXMLLoader.load(getClass().getResource("FXMLDocument.fxml"));
Scene scene = new Scene(root);
stage.setScene(scene);
stage.show();
}
/**
* #param args the command line arguments
*/
public static void main(String[] args) {
launch(args);
}
}
FXMLDocument.fxml
<AnchorPane id="AnchorPane" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="480.0" prefWidth="640.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1" fx:controller="manoj.FXMLDocumentController">
<children>
<AnchorPane layoutX="142.0" layoutY="36.0" prefHeight="361.0" prefWidth="360.0">
<children>
<Label fx:id="result" alignment="CENTER" contentDisplay="CENTER" layoutX="61.0" layoutY="289.0" opacity="0.51" prefHeight="77.0" prefWidth="169.0" text="Result Of Addition">
<font>
<Font size="18.0" />
</font>
</Label>
<Label layoutX="26.0" layoutY="108.0" prefHeight="32.0" prefWidth="90.0" text="Number#1 ">
<font>
<Font size="14.0" />
</font>
</Label>
<Label alignment="TOP_CENTER" contentDisplay="CENTER" text="First Application" textAlignment="CENTER">
<font>
<Font name="Cambria" size="50.0" />
</font>
</Label>
<Label layoutX="26.0" layoutY="155.0" prefHeight="32.0" prefWidth="90.0" text="Number#2">
<font>
<Font size="14.0" />
</font>
</Label>
<Button fx:id="button" alignment="CENTER" contentDisplay="CENTER" layoutX="83.0" layoutY="216.0" onAction="#addNumber" prefHeight="44.0" prefWidth="125.0" text="Add Number">
<font>
<Font name="Cambria" size="14.0" />
</font>
</Button>
<TextField fx:id="textone" layoutX="141.0" layoutY="108.0" prefHeight="32.0" prefWidth="179.0" />
<TextField fx:id="texttwo" layoutX="141.0" layoutY="155.0" prefHeight="32.0" prefWidth="179.0" />
</children>
<padding>
<Insets bottom="20.0" left="20.0" right="20.0" />
</padding>
</AnchorPane>
</children>
<padding>
<Insets top="20.0" />
</padding>
</AnchorPane>
FXMLDocumentController.java
public class FXMLDocumentController implements Initializable {
#FXML
private Label result;
private TextField textone;
public FXMLDocumentController() {
}
#FXML
private void addNumber(ActionEvent event) {
System.out.println("Clicked. !");
String str = textone.getText();
result.setText(str);
}
#Override
public void initialize(URL url, ResourceBundle rb) {
// TODO
}
}
I am developing using netbeans with scene builder. When I run this project and click Add Number button, I got an exception.
Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1768)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(FXMLLoader.java:1651)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:86)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:49)
at javafx.event.Event.fireEvent(Event.java:204)
at javafx.scene.Node.fireEvent(Node.java:8175)
at javafx.scene.control.Button.fire(Button.java:185)
at com.sun.javafx.scene.control.behavior.ButtonBehavior.mouseReleased(ButtonBehavior.java:182)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:96)
at com.sun.javafx.scene.control.skin.BehaviorSkinBase$1.handle(BehaviorSkinBase.java:89)
at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(CompositeEventHandler.java:218)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(CompositeEventHandler.java:80)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:238)
at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(EventHandlerManager.java:191)
at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(CompositeEventDispatcher.java:59)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:58)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(BasicEventDispatcher.java:56)
at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(EventDispatchChainImpl.java:114)
at com.sun.javafx.event.EventUtil.fireEventImpl(EventUtil.java:74)
at com.sun.javafx.event.EventUtil.fireEvent(EventUtil.java:54)
at javafx.event.Event.fireEvent(Event.java:204)
at javafx.scene.Scene$MouseHandler.process(Scene.java:3746)
at javafx.scene.Scene$MouseHandler.access$1800(Scene.java:3471)
at javafx.scene.Scene.impl_processMouseEvent(Scene.java:1695)
at javafx.scene.Scene$ScenePeerListener.mouseEvent(Scene.java:2486)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:314)
at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(GlassViewEventHandler.java:243)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(GlassViewEventHandler.java:345)
at com.sun.glass.ui.View.handleMouseEvent(View.java:526)
at com.sun.glass.ui.View.notifyMouse(View.java:898)
at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
at com.sun.glass.ui.win.WinApplication.access$300(WinApplication.java:39)
at com.sun.glass.ui.win.WinApplication$4$1.run(WinApplication.java:112)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at sun.reflect.misc.Trampoline.invoke(MethodUtil.java:71)
at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:483)
at sun.reflect.misc.MethodUtil.invoke(MethodUtil.java:275)
at javafx.fxml.FXMLLoader$MethodHandler.invoke(FXMLLoader.java:1763)
... 47 more
Caused by: java.lang.NullPointerException
at manoj.FXMLDocumentController.addNumber(FXMLDocumentController.java:33)
... 57 more
Please help me to get out of this exception. Thanks in advance.

Thanks for your comment Jose Pereda.
Just a simple careless mistake.
As Jose Pereda said, I added #FXML annotation for textone and it worked fine.

package net.remark.abs.invoice;
import java.util.Date;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.scene.layout.AnchorPane;
import net.remark.abs_bos.Invoice;
import net.rojer.core.db.DataBase;
import net.rojer.javafx.tool.Tools;
public class FrameInvoice extends AnchorPane{
#FXML
private TextField fldInvoiceNumber;
#FXML
private Label lblPrice;
public FrameInvoice(){
Tools.innitiateFxml(this);
}
#FXML
private void onSave (ActionEvent event){
Invoice invo = new Invoice();
invo.setDate(new Date());
invo.setTotal(0);
invo.setStat((true));
DataBase.begin();
DataBase.em().persist(invo);
DataBase.commit();
System.out.println("true");
}
}

I have seen many posts regarding this error and many of them get failed.For me it was the same. try to make the fxml file again and let the IDE to create the controller and css. keep the default controller and css names as it is and attach newly created '.fxml' file to the code. For me It worked.copy the content from the scene builder ,but not by the xml code.