playing .mp3 file in java using notepad

Question

I know this is a repeat question. check original one here or here.

So my code is just the copy paste :

import javafx.scene.media.*;

class Gui {
  public static void main(String[] args) {
    try{
        Media hit = new Media("skin.mp3");
        MediaPlayer mediaPlayer = new MediaPlayer(hit);
        mediaPlayer.play();
    }catch(Exception e){
        e.printStackTrace();
    }
  }
}

The exception which i'm getting is :

java.lang.IllegalArgumentException: uri.getScheme() == null!
        at com.sun.media.jfxmedia.locator.Locator.<init>(Locator.java:217)
        at javafx.scene.media.Media.<init>(Media.java:364)
        at Gui.main(gui.java:6)

I'm compiling & running it correctly i.e. by including the jfxrt.jar file in classpath

Note: I'm just using notepad instead of any IDE.

So can anyone tell me the reason of IllegalArgumentException

Thankx

UPDATE : By using file://e:/skin.mp3 it worked fine but left me with another exception :

MediaException: MEDIA_INACCESSIBLE : e
        at javafx.scene.media.Media.<init>(Unknown Source)
        at Gui.main(gui.java:6)

So if you can put some light on this exception.

By the way i've checked the song, its not corrupt because it is playing nicely in vlc.

Answer 1

There are a few problems with the code in this question.

1. The class needs to be public.
2. JavaFX 2 applications need to extend the Application class.
3. JavaFX 2 applications should define a start method.
4. The locator for the media being created should be a full URI as noted by MadProgrammer.

Even though the question has a javafx-2 tag, I wonder if it is written for JavaFX 1.x JavaFX Script (which is now an unsupported programming language and incompatible with JavaFX 2). If so, I'd recommend coding in Java and using JavaFX 2.x for this rather than JavaFX Script.

On Windows a file representation of an absolute locator of a URI has three slashes after the file protocol. For example, the following is valid:

file:///C:/Users/Public/Music/skin.mp3

For some reason, a single slash will also work (I guess internally Java will interpolate the extra // for the protocol specifier on files or perhaps there is something I don't understand in the URL specification which means that you don't need a // after the protocol).

file:/C:/Users/Public/Music/skin.mp3

One way to check the file uri for something is valid to ask if the file uri exists

System.out.println("File " + filename + " exists? " + new File(filename).exists()); 

After you know your file uri is valid, you can convert it to a string using.

file.toURI().toURL().toExternalForm()

Here is a short sample program for playing some audio in JavaFX using a MediaPlayer with a little bit of error handling, so that it is easier to understand if something goes wrong.

import java.io.File;
import java.net.MalformedURLException;
import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.control.Label;
import javafx.scene.layout.StackPane;
import javafx.scene.media.*;
import javafx.scene.paint.Color;
import javafx.stage.Stage;

/** plays an audio in JavaFX 2.x */
public class SimpleAudioPlayer extends Application {
  public static void main(String[] args) { launch(args); }
  @Override public void start(Stage stage) throws MalformedURLException {
    final Label status = new Label("Init");
    MediaPlayer mediaPlayer = createMediaPlayer(
      "C:/Users/Public/Music/Sample Music/Future Islands - Before the Bridge.mp3", 
      status
    );
    StackPane layout = new StackPane();
    layout.getChildren().addAll(status);
    stage.setScene(new Scene(layout, 600, 100, Color.CORNSILK));
    stage.show();
    if (mediaPlayer != null) {
      mediaPlayer.play();
    }  
  }

  /** 
   * creates a media player using a file from the given filename path 
   * and tracks the status of playing the file via the status label 
   */
  private MediaPlayer createMediaPlayer(final String filename, final Label status) throws MalformedURLException {
    File file = new File(filename);
    if (!file.exists()) {
      status.setText("File does not exist: " + filename);
    }
    final String mediaLocation = file.toURI().toURL().toExternalForm();
    Media media = new Media(mediaLocation);
    MediaPlayer mediaPlayer = new MediaPlayer(media);
    mediaPlayer.setOnError(new Runnable() {
      @Override public void run() {
        status.setText("Error");
      }
    });
    mediaPlayer.setOnPlaying(new Runnable() {
      @Override public void run() {
        status.setText("Playing: " + mediaLocation);
      }
    });
    mediaPlayer.setOnEndOfMedia(new Runnable() {
      @Override public void run() {
        status.setText("Done");
      }
    });
    return mediaPlayer;
  }
}

Here is a link to an additional example of a JavaFX 2.x media player which plays all of the mp3 files in a given directory sequentially.

Answer 2

From the JavaFX API docs

• The supplied URI must conform to RFC-2396 as required by java.net.URI.
• Only HTTP, FILE, and JAR URIs are supported.

So, I suspect from reading the docs, you need to supply a URI path.

Something like file://path/to/file/skin.mp3 will probably work.