WordPress: Display custom Meta box on specific page template only

wp_custom_meta_box_specific_page

/*awesome tip from http://www.paulund.co.uk/display-post-meta-box-specific-page-templates*/
add_action('add_meta_boxes', 'add_product_meta');
function add_product_meta()
{
    global $post;

    if(!empty($post))
    {
        $pageTemplate = get_post_meta($post->ID, '_wp_page_template', true);

        if($pageTemplate == 'page-templates/product-page.php' )
        {
            add_meta_box(
                'product_meta', // $id
                'Product Information', // $title
                'display_product_information', // $callback
                'page', // $page
                'normal', // $context
                'high'); // $priority
        }
    }
}

function display_product_information()
{
    // Add the HTML for the post meta
}

Hello Kosmiq,
Great job!
I just can not save these fields.

I'm trying to use something like:

function save_meta_page( $post_id ) {
$pageTemplate = get_post_meta($post_id, '_wp_page_template', true);

                if($pageTemplate == 'templates/mytemplate.php' ){
    if( isset($_POST['my_meta_value']) ) {
	update_post_meta( $post_id, 'my_meta_value', sanitize_text_field( $_POST['my_meta_value'] ) );
 }
 }

}
add_action('save_post', 'save_meta_page', 9999, 1);

How do I save these fields to the specific template?