How to add AnchorPane scene to BorderPane on button click?

Question

Java

I want to put an AnchorPane scene in a BorderPane scene which is in AnchorPane --> SplitPane --> BorderPane .
An exception is thrown:
java.lang.NullPointerException
Line error:
planOnDayBorderPane.setCenter(trampolinePark);
Scene where another scene needs to be moved, for example, a scene with a picture or just a table (PlanOnDay):

Main scene (there is a button on it, when clicked, a scene will be added) (RootLayout ):

PlanOnDay.fxml

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

<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<AnchorPane prefHeight="300.0" prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1"
            fx:controller="sample.view.controllers.SceneController">
    <children>
        <SplitPane dividerPositions="0.4" layoutX="128.0" layoutY="26.0" prefHeight="300.0" prefWidth="600.0"
                   AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0"
                   AnchorPane.topAnchor="0.0">
            <items>
                <AnchorPane minHeight="0.0" minWidth="0.0" prefHeight="160.0" prefWidth="100.0">
                    <children>
                        <TableView layoutX="18.0" layoutY="25.0" prefHeight="298.0" prefWidth="236.0"
                                   AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0"
                                   AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
                            <columns>
                                <TableColumn prefWidth="75.0" text="Action name"/>
                            </columns>
                            <columnResizePolicy>
                                <TableView fx:constant="CONSTRAINED_RESIZE_POLICY"/>
                            </columnResizePolicy>
                        </TableView>
                    </children>
                </AnchorPane>
                <BorderPane fx:id="planOnDayBorderPane" prefHeight="200.0" prefWidth="200.0"/>
            </items>
        </SplitPane>
    </children>
</AnchorPane>

RootLayout.fxml

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

<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>

<BorderPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="400.0"
            prefWidth="600.0" xmlns="http://javafx.com/javafx/8" xmlns:fx="http://javafx.com/fxml/1"
            fx:controller="sample.view.controllers.SceneController">
    <top>
        <MenuButton mnemonicParsing="false" text="Action" BorderPane.alignment="TOP_LEFT">
            <items>
                <MenuItem mnemonicParsing="false" onAction="#showTrampolinePark" text="Trampoline Park"/>
                <MenuItem mnemonicParsing="false" text="Cafe Milk"/>
                <MenuItem mnemonicParsing="false" text="Home"/>
            </items>
        </MenuButton>
    </top>
</BorderPane>

SceneController.java

package sample.view.controllers;

import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.FXMLLoader;
import javafx.scene.Scene;
import javafx.scene.layout.AnchorPane;
import javafx.scene.layout.BorderPane;
import sample.Main;

import java.io.IOException;

public class SceneController {

    @FXML
    private BorderPane planOnDayBorderPane;

    private Main main;

    public void showTrampolinePark(ActionEvent actionEvent) {
        try {
            FXMLLoader fxmlLoader = new FXMLLoader();
            fxmlLoader.setLocation(Main.class.getResource("view/TrampolinePark.fxml"));
            AnchorPane trampolinePark = fxmlLoader.load();

            planOnDayBorderPane.setCenter(trampolinePark);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Answer 1

Try.

FXMLLoader fxmlLoader = new FXMLLoader(LoaderFXML.class.getResource(fxml));
AnchorPane child = fxmlLoader.load(); // вот тут у Вас null, неправильная загрузка.
...
borderPane.setCenter(child );