Integrating MySQL Into JavaFX Scene Builder

I am new to javafx and my goal is to basically just test if my java code works with Mysql. What I'm planning to do is to display one data of the sakila database into a Label named greetingLabel. And I can't seem to find where i went wrong so i'll show you my whole code.

Here is the main code for my controller class from scene builder:

package main;
import java.net.URL;
import java.util.ResourceBundle;
import javafx.event.ActionEvent;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Label;

[Code] .....

Here is the error displayed when pressing the button

Exception in thread "JavaFX Application Thread" java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at javafx.fxml.FXMLLoader$MethodHandler.invoke(Unknown Source)
at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(Unknown Source)
at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)

[Code] .....