JavaFX Line draw arrow

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.layout.Pane;
import javafx.scene.layout.StackPane;
import javafx.scene.shape.Line;
import javafx.stage.Stage;

public class Main extends Application {
   @Override/*from  w  ww. j av  a2s.  c  o  m*/
   public void start(Stage primaryStage) {

      double startX = 10;
      double startY = 10;
      double endX = 200;
      double endY = 200;
      Pane arrowPane = new Pane();
      drawArrowLine(startX, startY, endX, endY, arrowPane);

      StackPane pane = new StackPane();
      pane.setPadding(new Insets(20));
      pane.getChildren().add(arrowPane);

      Scene scene = new Scene(pane);
      primaryStage.setTitle("java2s.com");
      primaryStage.setScene(scene);
      primaryStage.show();
   }

   public static void drawArrowLine(double startX, double startY, double endX, double endY, Pane pane) {
      // get the slope of the line and find its angle
      double slope = (startY - endY) / (startX - endX);
      double lineAngle = Math.atan(slope);

      double arrowAngle = startX > endX ? Math.toRadians(45) : -Math.toRadians(225);

      Line line = new Line(startX, startY, endX, endY);

      double lineLength = Math.sqrt(Math.pow(startX - endX, 2) + Math.pow(startY - endY, 2));
      double arrowLength = lineLength / 10;

      // create the arrow legs
      Line arrow1 = new Line();
      arrow1.setStartX(line.getEndX());
      arrow1.setStartY(line.getEndY());
      arrow1.setEndX(line.getEndX() + arrowLength * Math.cos(lineAngle - arrowAngle));
      arrow1.setEndY(line.getEndY() + arrowLength * Math.sin(lineAngle - arrowAngle));

      Line arrow2 = new Line();
      arrow2.setStartX(line.getEndX());
      arrow2.setStartY(line.getEndY());
      arrow2.setEndX(line.getEndX() + arrowLength * Math.cos(lineAngle + arrowAngle));
      arrow2.setEndY(line.getEndY() + arrowLength * Math.sin(lineAngle + arrowAngle));

      pane.getChildren().addAll(line, arrow1, arrow2);
   }

   public static void main(String[] args) {
      Application.launch(args);
   }
}