Main.java

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

public class Main extends Application {

    @Override
    public void start(Stage primaryStage) throws Exception{
        Parent root = FXMLLoader.load(getClass().getResource("sample.fxml"));
        primaryStage.setTitle("Hello World");
        primaryStage.setScene(new Scene(root));
        primaryStage.show();
    }


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

sample.fxml

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

<?import javafx.geometry.Insets?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.HBox?>
<?import javafx.scene.layout.StackPane?>

<StackPane maxWidth="1000.0" minHeight="-Infinity" minWidth="100.0" prefWidth="1000.0" style="-fx-border-color: black; -fx-border-width: 2px;" xmlns="http://javafx.com/javafx/8.0.102-ea" xmlns:fx="http://javafx.com/fxml/1">
    <children>
        <Label text="This is StackPane" StackPane.alignment="TOP_LEFT">
            <StackPane.margin>
                <Insets />
            </StackPane.margin>
        </Label>
        <HBox maxHeight="-Infinity" maxWidth="600.0" minHeight="-Infinity" minWidth="-Infinity" prefWidth="600.0" spacing="500.0" style="-fx-border-width: 2px; -fx-border-color: red;" StackPane.alignment="CENTER">
            <children>
                <Label text="This is HBox (parent=StackPane) with maxWidth = 600" />
            </children>
        </HBox>
        <AnchorPane maxWidth="600.0" minHeight="50.0" minWidth="100.0" prefHeight="200.0" prefWidth="600.0" style="-fx-border-color: green; -fx-border-width: 2px;">
            <children>
                <Label text="This is AnchorPane (parent=StackPane) with maxWidth = 600" />
                <Label layoutX="491.0" layoutY="54.0" text="This label has left anchor = 700" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="700.0" />
            </children>
            <StackPane.margin>
                <Insets bottom="40.0" top="40.0" />
            </StackPane.margin>
        </AnchorPane>

    </children>
</StackPane>