Reading Files Within a Jar(ZipInputStream, etc.)

Question

I'm writing a game in java and all is working more or less well, as you would expect when coding, but one issue I have come across is reading the image and sound files into the game. I wrote a method that works really well within Eclipse, but as soon as I try to test it in a runnable jar (exported using Eclipse) my game gets stuck on the loading screen because it can't read the files. I realized the problem there being that you cannot create File objects within a Jar, you have to use streams. This could work, but the images/sounds are located within folders and I'm not very sure how you can read files within a folder with streams(i.e not knowing the amount of files). Because of this I have tried to rewrite the method using the ZipInputStream (I found this as recommended when looking for solutions prior to posting this). This is what the method looks like now:

imageMap = new HashMap<String, BufferedImage>();
    String imagebase = "/images";
    CodeSource src = PlatformerCanvas.class.getProtectionDomain().getCodeSource();
    if(src != null)
    {
        URL jar = src.getLocation();
        try
        {
            ZipArchiveInputStream zip = new ZipArchiveInputStream(jar.openStream());
            ZipArchiveEntry ze = null;
            while((ze = zip.getNextZipEntry()) != null)
            {
                System.out.println(ze.getName());
                if(ze.getName().startsWith(imagebase) && ze.getName().endsWith(".png"))
                {
                    loading++;
                    imageMap.put(ze.getName().replaceAll(imagebase + "/", ""), ImageIO.read(this.getClass().getResource(ze.getName())));
                }
            }
            zip.close();
            System.out.println("Finished Loading Images");
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
    }

However, this completely skips over the while loop because getNextZipEntry return null. I tried using the base Zip archive libraries, but someone recommended the Apache Commons libraries, but neither worked. My Jar setup is this:

Jar
/game/gameClasses
/images/imageFiles
/sounds/soundFiles
/whateverOtherFoldersEclipseCreated

So my question is this: Why isn't this current method working and how do I fix it? Or, how can I load the images/sounds in a different way that works? I have looked at many other questions and tried many different things, but none worked for me.

Not 100% sure what you mean, but I use a buffer strategy to do the drawing onto a canvas. @JtheRocker — StrongJoshua, Jul 07 '13 at 20:10
Why not keep the resources in the resource folder, if you are embedding everything in a jar? — SSaikia_JtheRocker, Jul 07 '13 at 20:17

score 1 · Accepted Answer · answered Jul 08 '13 at 05:10

1

Or, how can I load the images/sounds in a different way that works?

One common technique is to include a list of resources in a known location in the Jar. Read the list, then iterate the lines (presuming one line per resource) & read the paths that way.

answered Jul 08 '13 at 05:10

Andrew Thompson

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This, I may end up doing, but is there a way to have the method check whether I'm running it from a jar or from Eclipse (does checking the path for the word "jar" work?). – StrongJoshua Jul 08 '13 at 13:10
So what I did was I made a little class that would "package" all images and sounds into a .txt file which would be read if the game was being run from a Jar (if(checkJar.rsrc)). I now have another problem, but this one is resolved. Thank you :) – StrongJoshua Jul 08 '13 at 17:31

Reading Files Within a Jar(ZipInputStream, etc.)

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