Java Musikplayer (Projekt) funktioniert nicht

package Controller;


import java.io.File;
import java.io.IOException;
import java.net.URL;
import java.util.ResourceBundle;


import javafx.beans.InvalidationListener;
import javafx.beans.Observable;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.event.ActionEvent;
import javafx.event.EventHandler;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.control.Button;
import javafx.scene.control.Slider;
import javafx.scene.input.MouseEvent;
import javafx.scene.layout.Pane;
import javafx.scene.media.Media;
import javafx.scene.media.MediaPlayer;
import javafx.util.Duration;


// onDragDropped="#PaneDragAndDrop" fx:id="#DragAndDropPane"
public class MainFXController implements Initializable {


	@FXML public static Pane DragAndDropPane;
	@FXML private Slider volumeSlider;
	@FXML private Slider seeSlider;
	@FXML private Button btnPrevious;
	@FXML private Button btnPlay;
	@FXML private Button btnStop;
	@FXML private Button btnNext;
	Media sound = new Media(new File("src/musicmain/1.mp3").toURI().toString());
	MediaPlayer mediaPlayer = new MediaPlayer(sound);


	@Override
	public void initialize(URL location, ResourceBundle resource) {
		volumeSlider.setValue(mediaPlayer.getVolume() * 100);
		volumeSlider.valueProperty().addListener(new InvalidationListener() {


			@Override
			public void invalidated(Observable observable) {
				mediaPlayer.setVolume(volumeSlider.getValue() / 100);
			}
		});
		mediaPlayer.currentTimeProperty().addListener(new ChangeListener<Duration>() {


			@Override
			public void changed(ObservableValue<? extends Duration> observable, Duration oldValue, Duration newValue) {
				seeSlider.setValue(newValue.toSeconds());
			}
		});
	}
	@FXML 
	protected void seeSlider(MouseEvent event) {
		mediaPlayer.seek(Duration.seconds(seeSlider.getValue()));
	}
	@FXML 
    protected void btnPlay(ActionEvent event) throws IOException {
		mediaPlayer.play();
	}
	@FXML 
    protected void btnStop(ActionEvent event) throws IOException {
		mediaPlayer.stop();
	}


}