Firas Chebbah Firas Chebbah - 7 months ago 36
Java Question

javafx : javafx.scene.layout.AnchorPane cannot be cast to javafx.scene.layout.BorderPane

hey guys i am knew to javafx and i am trying to cast a BorderPane to an anchronPane, meanwhile an error occured and i don t know what to do, i was following a tutorial so please help

package ch.makery.address;
import java.io.IOException;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
public class MainApp extends Application {

private Stage primaryStage;
private BorderPane rootLayout;

@Override
public void start(Stage primaryStage) {
this.primaryStage = primaryStage;
this.primaryStage.setTitle("AddressApp");

initRootLayout();

showPersonOverview();
}

/**
* Initializes the root layout.
*/
public void initRootLayout() {
try {
// Load root layout from fxml file.
FXMLLoader loader = new FXMLLoader();
loader.setLocation(MainApp.class.getResource("view/RootLayout.fxml"));
rootLayout = (BorderPane) loader.load();

// Show the scene containing the root layout.
Scene scene = new Scene(rootLayout);
primaryStage.setScene(scene);
primaryStage.show();
} catch (IOException e) {
e.printStackTrace();
}
}

/**
* Shows the person overview inside the root layout.
*/
public void showPersonOverview() {
try {
// Load person overview.
FXMLLoader loader = new FXMLLoader();
loader.setLocation(MainApp.class.getResource("view/PersonOverview.fxml"));
AnchorPane personOverview = (AnchorPane) loader.load();

// Set person overview into the center of root layout.
rootLayout.setCenter(personOverview);
} catch (IOException e) {
e.printStackTrace();
}
}

/**
* Returns the main stage.
* @return
*/
public Stage getPrimaryStage() {
return primaryStage;
}

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


and i am getting this error

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:483)
at com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:367)
at com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:305)
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.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:767)
Caused by: java.lang.RuntimeException: Exception in Application start method
atcom.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:894)
at com.sun.javafx.application.LauncherImpl.access$000(LauncherImpl.java:56)
at com.sun.javafx.application.LauncherImpl$1.run(LauncherImpl.java:158)
at java.lang.Thread.run(Thread.java:745)
Caused by: java.lang.ClassCastException: javafx.scene.layout.AnchorPane cannot be cast to javafx.scene.layout.BorderPane
at ch.makery.address.MainApp.initRootLayout(MainApp.java:35)
at ch.makery.address.MainApp.start(MainApp.java:22)
at com.sun.javafx.application.LauncherImpl$8.run(LauncherImpl.java:837)
at com.sun.javafx.application.PlatformImpl$7.run(PlatformImpl.java:335)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:301)
at com.sun.javafx.application.PlatformImpl$6$1.run(PlatformImpl.java:298)
at java.security.AccessController.doPrivileged(Native Method)
at com.sun.javafx.application.PlatformImpl$6.run(PlatformImpl.java:298)
atcom.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.ja va:95)
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)
... 1 more


Exception running application ch.makery.address.MainApp
Java Result: 1

so if i cannot cast then what sould i do?

Answer

BorderPane extends Pane

AnchorPane extends Pane

They extend the same class but are different classes and generate different objects that can not be casted into each other.


Practical example

Lion extends BigCat

Tiger extends BigCat

How would you cast a Lion to a Tiger ?

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