Java - Export to JAR file in eclipse with resources (images and audio files)

Question

I use eclipse on linux Ubuntu and I have this code for loading image and setting it as background in one of my JPanels:

public class MenuState extends JPanel implements ActionListener {

private static final long serialVersionUID = 1L;
private GameStateManager gsm;
private int width;
private int height;

public MenuState(GameStateManager gsm)
{
    this.gsm = gsm;
    width = gsm.getWidth();
    height = gsm.getHeight();
    SizeManager sm = new SizeManager();
    this.setLayout(new BorderLayout());
    sm.set_size(this, width, height);
}

public void paintComponent(Graphics g)
{
    super.paintComponent(g);

    BufferedImage background_image;
    try {
        background_image = ImageIO.read(new File("src/res/img/menu_background.png"));
        g.drawImage(background_image, 0, 0, width, height, null);
    } catch (IOException e) {
        e.printStackTrace();
    }
}

public void actionPerformed(ActionEvent e) {
}

and it works only in eclipse. When I export it to jar file or runnable jar file program does not show images. I also tried to use

this.getClass().getResource()

and similar codes but it does not work in eclipse. But I am maybe doing something wrong.

I also have this code in another class to play audio:

public class AudioManager {

private Clip clip;

public void play(String audio_name, boolean repeat)
{   
    try {
        File audioFile = new File(audio_name);
        AudioInputStream audioStream = AudioSystem.getAudioInputStream(audioFile);
        AudioFormat format = audioStream.getFormat();
        DataLine.Info info = new DataLine.Info(Clip.class, format);
        clip = (Clip) AudioSystem.getLine(info);
        clip.open(audioStream);
        if(repeat)
        {
            clip.loop(clip.LOOP_CONTINUOUSLY);
        }
        clip.start();

    } catch (Exception e) {
        e.printStackTrace();
    }
}

public void stop()
{
    clip.stop();
}

and it plays audio in eclipse but not after I export project.

I suppose File works only for files on disk and not for files in jar file but it is only way I made it works in eclipse.

So, what should I do?

And additional problem: Sound played in eclipse is lagging, I improved it increasing available memory for eclipse but little lags occur when loading program and changing JPanels in JFrame by clicking on JButtons.

Thanks for any advice.

Answer 1

What String do you put into the getResource method ? When you use getResource or getResourceAsStream , you must specify the package path. If your file is in the package "com.test.example", then you must put getResource("/com/test/example/my_file.png") .

So, with your background image, you must load your image with :

background_image = ImageIO.read(this.getClass().getResource("/res/img/menu_background.png"));

You should do the same way with your audio file.

I also recommend you to load your image outside of the paintComponent method. Otherwise, each time your panel is repainted, the image is reloaded.