CODEWITHSUNDEEP
javajavafxjavafx-8
Kiraged
Kiraged

Reputation: 519

FileChooser in JavaFX giving NullPointerException

This is my class:

package com.movie;

import java.io.File;

import java.net.URL;
import java.util.ResourceBundle;

import javafx.beans.property.BooleanProperty;
import javafx.beans.property.SimpleBooleanProperty;
import javafx.fxml.FXML;
import javafx.fxml.Initializable;
import javafx.scene.image.Image;
import javafx.scene.image.ImageView;
import javafx.scene.layout.BorderPane;
import javafx.scene.media.Media;
import javafx.scene.media.MediaPlayer;
import javafx.scene.media.MediaView;
import javafx.stage.FileChooser;

public class MoviePlayerController implements Initializable {

    private BooleanProperty play = new SimpleBooleanProperty(true);

    @FXML
    private BorderPane borderPane;

    @FXML
    private MediaView mediaView;

    @FXML
    private ImageView playView;

    @Override
    public void initialize(URL location, ResourceBundle resources) {
        onStartUp();
        playView.setImage(new Image(getClass().getResource("Pause.png").toExternalForm()));
        playView.setVisible(false);
        playView.setOnMouseClicked(event -> onPlayView());
    }

    public void onStartUp() {
        try {
            FileChooser fileChooser = new FileChooser();
            File file = fileChooser.showOpenDialog(borderPane.getScene().getWindow());
            if(file != null) {
                mediaView.toFront();
                mediaView.setMediaPlayer(new MediaPlayer(new Media(file.toURI().toURL().toExternalForm())));
                mediaView.getMediaPlayer().play();
                playView.setVisible(true);
                playView.toFront();
            }
        } catch(Exception e) {
            e.printStackTrace();
        }
    }

    public void onPlayView() {
        if(play.get()) {
            playView.setImage(new Image(getClass().getResource("Resume.png").toExternalForm()));
            mediaView.getMediaPlayer().pause();
            play.set(false);
        } else {
            playView.setImage(new Image(getClass().getResource("Pause.png").toExternalForm()));
            mediaView.getMediaPlayer().play();
            play.set(true);
        }
    }
}

I'm getting this error:

java.lang.NullPointerException
    at com.movie.MoviePlayerController.onStartUp(MoviePlayerController.java:44)
    at com.movie.MoviePlayerController.initialize(MoviePlayerController.java:35)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2542)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:2435)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3208)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3169)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3142)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3118)
    at javafx.fxml.FXMLLoader.loadImpl(FXMLLoader.java:3098)
    at javafx.fxml.FXMLLoader.load(FXMLLoader.java:3091)
    at com.movie.MoviePlayer.start(MoviePlayer.java:19)
    at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$153(LauncherImpl.java:821)
    at com.sun.javafx.application.LauncherImpl$$Lambda$51/1616271442.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$166(PlatformImpl.java:323)
    at com.sun.javafx.application.PlatformImpl$$Lambda$44/1051754451.run(Unknown Source)
    at com.sun.javafx.application.PlatformImpl.lambda$null$164(PlatformImpl.java:292)
    at com.sun.javafx.application.PlatformImpl$$Lambda$47/1814330183.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.application.PlatformImpl.lambda$runLater$165(PlatformImpl.java:291)
    at com.sun.javafx.application.PlatformImpl$$Lambda$46/1775282465.run(Unknown Source)
    at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:95)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$141(WinApplication.java:102)
    at com.sun.glass.ui.win.WinApplication$$Lambda$37/1109371569.run(Unknown Source)
    at java.lang.Thread.run(Thread.java:745)

This is line 44: File file = fileChooser.showOpenDialog(borderPane.getScene().getWindow());

This is line 35: playView.setOnMouseClicked(event -> onPlayView());

Before this i used a StackPane and you had to click on a button to open the FileChooser and that worked fine but now im using a BorderPane and i want the FileChooser to open when the application opens. And yes i set all the fx:id in the FXML file.

Upvotes: 1

Views: 1129

Answers (1)

isnot2bad
isnot2bad

Reputation: 24444

It is too soon to open the file dialog in the initialize method of a JavaFX controller. When this method is called, the FXML node tree is still in loading + initialization phase, so it has not been attached to the Scene yet.

So getScene() returns null.

You have to call onStartup() later, when the scene graph has been fully initialized. You can do that via Platform.runLater():

@Override
public void initialize(URL location, ResourceBundle resources) {
    playView.setImage(new Image(getClass().getResource("Pause.png").toExternalForm()));
    playView.setVisible(false);
    playView.setOnMouseClicked(event -> onPlayView());
    Platform.runLater(this::onStartup);
}

Upvotes: 2

Related Questions