Standalone FX dnd

package fxtest;

import java.io.BufferedOutputStream;
import java.nio.ByteBuffer;
import java.util.Arrays;

import javafx.application.Application;
import javafx.event.EventHandler;
import javafx.scene.Scene;
import javafx.scene.input.ClipboardContent;
import javafx.scene.input.DataFormat;
import javafx.scene.input.DragEvent;
import javafx.scene.input.Dragboard;
import javafx.scene.input.MouseEvent;
import javafx.scene.input.TransferMode;
import javafx.scene.layout.Pane;
import javafx.stage.Stage;

public class App extends Application {
    DataFormat refTrans = new DataFormat("MyDraggable");
    public static void main(String[] args) {
        launch(args);
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        final Pane pane = new Pane();
        pane.setOnDragDetected(new EventHandler<MouseEvent>() {

            @Override
            public void handle(MouseEvent event) {
            Dragboard db = pane.startDragAndDrop(TransferMode.COPY_OR_MOVE);
                ClipboardContent content = new ClipboardContent();
                BufferedOutputStream o = null;
                content.put(refTrans, "FromFX");
                db.setContent(content);

                event.consume();
            }
        });
        pane.setOnDragEntered(new EventHandler<DragEvent>() {

            @Override
            public void handle(DragEvent event) {
                System.out.println("DragEntered");
                for(DataFormat df : event.getDragboard().getContentTypes()){
                    System.out.println(df.equals(refTrans));
                }

            }
        });
        Scene scene = new Scene(pane, 800, 600);
        primaryStage.setScene(scene);
        primaryStage.show();
    }

}