Issue
I am trying to load the FXML file and show it as an application window, but i get an exception. The FXML file was created by the FXML Scene Builder.
Here are the codes for the class
public class Main extends Application {
public static void main(String[] args) {
launch(args);
}
@Override
public void start(Stage primaryStage) throws Exception {
primaryStage.setScene(FXMLLoader.load(getClass().getResource("sample.fxml")));
primaryStage.show();
}
}
and FXML file
<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.TitledPane?>
<?import javafx.scene.layout.AnchorPane?>
<TitledPane animated="false" maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity"
prefHeight="400.0" prefWidth="600.0" text="Pass4D" xmlns:fx="http://javafx.com/fxml/1"
xmlns="http://javafx.com/javafx/8">
<content>
<AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="180.0" prefWidth="200.0">
<children>
<Button layoutX="211.0" layoutY="134.0" mnemonicParsing="false" prefHeight="33.0" prefWidth="177.0"
text="Log in"/>
<Button layoutX="212.0" layoutY="170.0" mnemonicParsing="false" prefHeight="33.0" prefWidth="175.0"
text="Exit"/>
</children>
</AnchorPane>
</content>
</TitledPane>
And here is the exception i get
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:875)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$147(LauncherImpl.java:157)
at com.sun.javafx.application.LauncherImpl$$Lambda$1/2074407503.run(Unknown Source)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.NullPointerException: Location is required.
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3201)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3169)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3142)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3118)
at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3098)
at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3091)
at Pass4D.start(Pass4D.java:19)
at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(LauncherImpl.java:821)
at com.sun.javafx.application.LauncherImpl$$Lambda$51/317090070.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(PlatformImpl.java:323)
at com.sun.javafx.application.PlatformImpl$$Lambda$47/1833150059.run(Unknown Source)
at com.sun.javafx.application.PlatformImpl.lambda$null$164(PlatformImpl.java:292)
at com.sun.javafx.application.PlatformImpl$$Lambda$49/2115863517.run(Unknown Source)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(PlatformImpl.java:291)
at com.sun.javafx.application.PlatformImpl$$Lambda$48/1436737924.run(Unknown Source)
at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
What am i doing wrong?
p.s. here is the project structure
Solution
The short answer is getClass().getResource("sample.fxml")
returns null
silently if the resource cannot be found on the runtime classpath, not the current directory etc.
So this depends on your IDE project setup, if you're using eclipse try adding the folder that sample.fxml
resides in the run configuration.
Some ideas...
- try
getClass().getResource("/sample.fxml")
instead... - try moving
sample.fxml
into the resources folder. I don't know much about your IDE, but I suspect that folder is only used for.java
files... this is certainly true for gradle projects in eclipse - resources have to be in thesrc/main/resources
tree as only that is added to the runtime classpath...
Answered By - Adam
Answer Checked By - Pedro (JavaFixing Volunteer)