initiate pane by fxml code example

Example: fxml padding

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

<?import java.net.*?>
<?import javafx.geometry.*?>
<?import javafx.scene.control.*?>
<?import javafx.scene.layout.*?>
<?import javafx.scene.text.*?>


<GridPane fx:controller="fxmlexample.FXMLExampleController" 
    xmlns:fx="http://javafx.com/fxml" alignment="center" hgap="10" vgap="10"
    styleClass="root">
    <padding><Insets top="25" right="25" bottom="25" left="25"/></padding>
    
    <Text id="welcome-text" text="Welcome" 
         GridPane.columnIndex="0" GridPane.rowIndex="0"
        GridPane.columnSpan="2"/>
 
    <Label text="User Name:"
        GridPane.columnIndex="0" GridPane.rowIndex="1"/>
 
    <TextField 
        GridPane.columnIndex="1" GridPane.rowIndex="1"/>
 
    <Label text="Password:"
        GridPane.columnIndex="0" GridPane.rowIndex="2"/>
 
    <PasswordField fx:id="passwordField" 
        GridPane.columnIndex="1" GridPane.rowIndex="2"/>
        
    <HBox spacing="10" alignment="bottom_right" 
        GridPane.columnIndex="1" GridPane.rowIndex="4">
        <Button text="Sign In"     
        onAction="#handleSubmitButtonAction"/>
    </HBox>

    <Text fx:id="actiontarget"
        GridPane.columnIndex="1" GridPane.rowIndex="6"/>
        
    <stylesheets>      <URL value="@Login.css" />    </stylesheets>
</GridPane>