javafx - Exception in Application start method

Question

I'm new to javafx and i was trying to make a gui from which when a button is clicked, it would go to another window. I tried reading many answers found on Stack Overflow. I even tried making the project again from the beginning...But i keep on getting the same error.

That is Exception is Application start method java.lang.reflect.InvocationTargetException javafx

My Main

import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class SkyTravelsFx extends Application {

    @Override
    public void start(Stage stage) throws Exception {
        Parent root = FXMLLoader.load(getClass().getResource("Login.fxml"));
        stage.initStyle(StageStyle.UNDECORATED);

        Scene scene = new Scene(root);

        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }

}

LoginController.java

package skytravelsfx;

import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.fxml.Initializable;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.TextField;
import javafx.stage.Stage;
import javafx.stage.StageStyle;

public class LoginController implements Initializable {

    @FXML
    TextField username;

    @FXML
    TextField password;

    @FXML
    Button user;

    @FXML
    Button admin;

    @FXML
    Button login;

    @FXML
    public void btnClicked (ActionEvent actionEvent){
        try{
            FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("User.fxml"));
            Parent root=(Parent) fxmlLoader.load();
            Stage stage = new Stage();
            Scene scene = new Scene(root);
            stage.setScene(scene);
            stage.initStyle(StageStyle.UNDECORATED);
            stage.show();
           ((Stage)(((Button)actionEvent.getSource()).getScene().getWindow())).hide();
        }catch(Exception e){
            e.printStackTrace();
        }
    }

    @Override
    public void initialize(URL location, ResourceBundle resources) {
        throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.
    }
}

Please note that i still haven't written any codes in UserController.java I just made the ui for User.fxml

Login.fxml

 <?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.image.*?>
<?import javafx.scene.shape.*?>
<?import javafx.scene.text.*?>
<?import java.lang.*?>
<?import java.util.*?>
<?import javafx.scene.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<AnchorPane id="AnchorPane" prefHeight="766.0" prefWidth="1366.0" xmlns:fx="http://javafx.com/fxml/1" xmlns="http://javafx.com/javafx/8" fx:controller="skytravelsfx.LoginController">
    <children>
      <ImageView fitHeight="866.0" fitWidth="1397.0" layoutX="10.0" layoutY="11.0" pickOnBounds="true" preserveRatio="true">
         <image>
            <Image url="@../../../SkyTravelFx/src/goodwp.com_25168.jpg" />
         </image>
      </ImageView>
        <Label fx:id="label" layoutX="126" layoutY="120" minHeight="16" minWidth="69" />
      <Label fx:id="label1" layoutX="565.0" layoutY="517.0" minHeight="16" minWidth="69" text="Select User">
         <font>
            <Font size="18.0" />
         </font>
      </Label>
      <Rectangle arcHeight="5.0" arcWidth="5.0" fill="#095a77" height="140.0" stroke="BLACK" strokeType="INSIDE" strokeWidth="0.0" width="1386.0" />
      <Label fx:id="label11" layoutX="56.0" layoutY="33.0" minHeight="16" minWidth="69" text="Sky Travels" textFill="WHITE">
         <font>
            <Font name="System Italic" size="72.0" />
         </font>
      </Label>
      <Label fx:id="label12" layoutX="432.0" layoutY="91.0" minHeight="16" minWidth="69" text="Making your destination closer..." textFill="WHITE">
         <font>
            <Font name="System Italic" size="18.0" />
         </font>
      </Label>
      <AnchorPane layoutX="83.0" layoutY="252.0" prefHeight="507.0" prefWidth="383.0">
         <children>
            <ImageView fitHeight="191.0" fitWidth="234.0" layoutX="96.0" layoutY="6.0" pickOnBounds="true" preserveRatio="true">
               <image>
                  <Image url="@../../../SkyTravelFx/src/icon-default-profile.png" />
               </image>
            </ImageView>
              <Button fx:id="login" layoutX="153.0" layoutY="440.0" onAction="#handleButtonAction" style="-fx-background-color: #095a77;" text="Log In" textFill="WHITE">
               <font>
                  <Font size="18.0" />
               </font>
            </Button>
            <Label fx:id="label2" layoutX="152.0" layoutY="308.0" minHeight="16" minWidth="69" text="Password">
               <font>
                  <Font size="18.0" />
               </font>
            </Label>
            <Label fx:id="label2" layoutX="150.0" layoutY="214.0" minHeight="16" minWidth="69" text="Username">
               <font>
                  <Font size="18.0" />
               </font>
            </Label>
            <TextField fx:id="username" layoutX="115.0" layoutY="241.0" />
            <TextField fx:id="password" layoutX="115.0" layoutY="335.0" />
         </children>
      </AnchorPane>
      <Button fx:id="admin" layoutX="621.0" layoutY="592.0" mnemonicParsing="false" style="-fx-background-color: #095a77;" text="Log In as Admin" textFill="WHITE">
         <font>
            <Font size="18.0" />
         </font>
      </Button>
      <Button fx:id="user" layoutX="621.0" layoutY="675.0" mnemonicParsing="false" onAction="#btnClicked" prefHeight="39.0" prefWidth="153.0" style="-fx-background-color: #095a77;" text="Log In as User" textFill="WHITE">
         <font>
            <Font size="18.0" />
         </font>
      </Button>
    </children>
</AnchorPane>

Here is the run-time error i am getting.

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$155(LauncherImpl.java:182) at java.lang.Thread.run(Thread.java:745) Caused by: javafx.fxml.LoadException: Error resolving onAction='#handleButtonAction', either the event handler is not in the Namespace or there is an error in the script. file:/C:/Users/Dell/Documents/NetBeansProjects/SkyTravelsFx/dist/run1245920268/SkyTravelsFx.jar!/skytravelsfx/Login.fxml:47

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$ValueElement.processEndElement(FXMLLoader.java:770) at javafx.fxml.FXMLLoader.processEndElement(FXMLLoader.java:2823) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2532) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2441) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3214) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3175) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3148) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3124) at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3104) at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3097) at skytravelsfx.SkyTravelsFx.start(SkyTravelsFx.java:23) at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$162(LauncherImpl.java:863) at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$175(PlatformImpl.java:326) at com.sun.javafx.application.PlatformImpl.lambda$null$173(PlatformImpl.java:295) at java.security.AccessController.doPrivileged(Native Method) at com.sun.javafx.application.PlatformImpl.lambda$runLater$174(PlatformImpl.java:294) at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95) at com.sun.glass.ui.win.WinApplication._runLoop(Native Method) at com.sun.glass.ui.win.WinApplication.lambda$null$148(WinApplication.java:191) ... 1 more Exception running application skytravelsfx.SkyTravelsFx Java Result: 1 Deleting directory C:UsersDellDocumentsNetBeansProjectsSkyTravelsFxdist un1245920268 jfxsa-run: BUILD SUCCESSFUL (total time: 4 seconds)

Answer 1

The stack trace tells you the problem:

Error resolving onAction='#handleButtonAction', either the event handler is not in the Namespace or there is an error in the script.

You have

<Button fx:id="login" layoutX="153.0" layoutY="440.0" onAction="#handleButtonAction" ... >

but your controller has no method called handleButtonAction. You probably want

<Button fx:id="login" layoutX="153.0" layoutY="440.0" onAction="#btnClicked" ... >