getting error when using controller in fxml file JAVA Code

Question

Why does this error happen?

Here is the code :

Main.java

public class Main extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {
        Parent root = FXMLLoader.load(getClass().getResource("Screen.fxml"));
        Scene scene = new Scene(root);
        primaryStage.setScene(scene);
    }
    
    public static void main(String[] args) {
        launch(args);
    }
}

Hhlee.java

public class Hhlee implements Initializable {
    @FXML private Button btn1, btn2, btn3;
    
    @Override
    public void initialize(URL location , ResourceBundle resources) {
        btn1.setOnAction(event -> handleBtn1Action(event));
        btn2.setOnAction(event -> handleBtn2Action(event));
        btn2.setOnAction(event -> handleBtn3Action(event));
    }
    
    public void handleBtn1Action(ActionEvent event) {
        System.out.println("버튼1 클릭");
    }
    
    public void handleBtn2Action(ActionEvent event) {
        System.out.println("버튼2 클릭");
    }
    
    public void handleBtn3Action(ActionEvent event) {
        System.out.println("버튼3 클릭");
    }
}

Screen.fxml

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

<HBox xmlns="http://javafx.com/javafx/16" xmlns:fx="http://javafx.com/fxml/1"
        prefWidth="300.0" hgap="10.0" vgap="10.0"
        fx:controller="application.Hhlee"
        prefHeight="50.0" prefWidth="200.0" alignment="CENTER" spacing="20.0">
    <Button fx:id="btn1" text="버튼1"/>
    <Button fx:id="btn2" text="버튼2"/>
    <Button fx:id="btn3" text="버튼3"/>
</HBox>

Fist, i think that fx:controller="PackageName.ClassName" Examine a Screen.fxml many times, But all of that Okay.

Second, Examine a fxml Path:

Package Explorer

Scribe error code below

Exception in Application start method
java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:363)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1071)
        Caused by: java.lang.RuntimeException: Exception in Application start method
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:900)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
    at java.base/java.lang.Thread.run(Thread.java:831)
    Caused by: java.lang.NullPointerException: Location is required.
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3230)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3194)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3163)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3136)
    at javafx.fxml/javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3113)
    at javafx.fxml/javafx.fxml.FXMLLoader.load(FXMLLoader.java:3106)

0009laH · Accepted Answer · 2021-07-29 13:00:29Z

1

When you invoke an FXML file via getClass().getRessource(path), you must provide a relative path starting from the location of your current class.

I would recommend you:

To put Screen.fxml inside the ui folder
Load it with the instruction: FXMLLoader.load(Main.class.getResource("../ui/Screen.fxml"));.

edited Jul 29, 2021 at 13:00

answered Jul 29, 2021 at 12:53

0009laH

1,9981 gold badge15 silver badges29 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Dharman · Accepted Answer · 2021-07-29 16:52:54Z

0

I was facing a similar issue, and similar to what @0009laH has said, I put all the files Main.java , Hhlee.java , Screen.fxml in one package, that is in the App/src/application. That way, you won't have to specify the relative path every time, and you can just directly use this:

public class Main extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {
         FXMLLoader loader=new FXMLLoader(getClass().getResource("Screen.fxml"));
         Parent root=(Parent) loader.load();
         Scene scene = new Scene(root);
         primaryStage.setScene(scene);
    }
    
    public static void main(String[] args) {
        launch(args);
    }
}

edited Jul 29, 2021 at 16:52

Dharman♦

33.9k27 gold badges106 silver badges157 bronze badges

answered Jul 29, 2021 at 16:47

Paramesh Sriram

8411 bronze badges

1 Comment

Paul Over a year ago

Thank for your help. i am appricaite your answer

Collectives™ on Stack Overflow

getting error when using controller in fxml file JAVA Code

2 Answers 2

Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related