Question

I’m using AQuery to help cache some images. I know for fact the images are being cached correctly, but I’m having trouble accessing them unless I’m online.

I know they are being cached because I can see them on my SD card and if I replace mArtistImageURL in my return statement with the URL from my browser (copy/paste), the image will load while I’m offline, if it’s already cached. I realize that I’m requesting to fetch the image URLs only if I’m online, but even so, I don’t understand why the cached images won’t load offline.

MusicUtils.isOnline() is basically a check to see if there is any connection. The main reason I have the bulk of my doInBackground() method wrapped in this is do to an Exception being thrown if I don’t. FATAL EXCEPTION: AsyncTask #1 is all Logcat is putting out for me at the moment. I’m not sure why the stacktrace isn’t complete.

I’ve tried using my AsyncTask in every way I know. I’ve returned a Bitmap, File, and String and I’m able to successfully load the image in each case, as long as I’m online. So, I have these cached images and I need some help putting them to use.

AsyncTask

    public class loadArtistImage extends AsyncTask<String, Integer, Bitmap> {
    @Override
    protected Bitmap doInBackground(String... arg0) {
        // Get artist image
        if (MusicUtils.isOnline(mContext)) {
            mArtistResults = Artist.getImages("Andrew Bird", 1, 1, key);
            mArtistIterator = mArtistResults.getPageResults().iterator();
            while (mArtistIterator.hasNext()) {
                mArtistImageURL = mArtistIterator.next().getImageURL(
                        ImageSize.ORIGINAL);
            }
        }
        aq.cache(mArtistImageURL, 60000 * 1440);
        return aq.getCachedImage(mArtistImageURL);
    }

    @Override
    protected void onPostExecute(Bitmap result) {
        bm = result;
        if (bm!= null) {
            mArtistImage.postDelayed(new Runnable() {
                @Override
                public void run() {
                    mArtistImage.startAnimation(AnimationUtils
                            .loadAnimation(mContext, android.R.anim.fade_in));
                    MusicUtils.setArtistBackground(mArtistImage, bm);
                }
            }, 666);
        } else {
            // TODO something
        }
        super.onPostExecute(result);
    }
}

Answer 1

Mm. While offline what the value of mArtistImageURL will be? Null? So at this point aq.cache(mArtistImageURL, 60000 * 1440); you are caching null, and at next line you are trying to get cache for null? Am I right?

Update: I suppose you cache images using url hash value for file name or something like this. So, modify your cache method to accept additional parameter for filename, for example aq.cache(mArtistImageURL,mArtistNameWithoutSpaces, 60000 * 1440); and when you want a file offline just call aq.getCachedImage(mArtistNameWithoutSpaces); so it will look at your cache folder and return a right file, or stub image if no file is found.

Update 2: Okay, if you dont want to modify AQuery cache methods you can try (againg) using shared preferences (so they would work) like this (not tested):

public String getUrlForArtist(String artistName) {
        SharedPreferences settings = mContext.getSharedPreferences(
                "artistImages", 0);
        return settings.getString(artistName, "http://default.url");
    }

public void setUrlForArtist(String artistName, String url) {
        SharedPreferences settings = mContext.getSharedPreferences(
                "artistImages", 0);
        SharedPreferences.Editor editor = settings.edit();
        editor.putString(artistName, url);
        editor.commit();
}

So in the end your code will look something like this:

if (MusicUtils.isOnline(mContext)) {
            mArtistResults = Artist.getImages("Andrew Bird", 1, 1, key);
            mArtistIterator = mArtistResults.getPageResults().iterator();
            while (mArtistIterator.hasNext()) {
                mArtistImageURL = mArtistIterator.next().getImageURL(
                        ImageSize.ORIGINAL);
            if(mArtistImageURL!=null)
             setUrlForArtist("Andrew Bird", mArtistImageURL);
            }
        } else
              mArtistImageURL = getUrlForArtist("Andrew Bird");

Oh, yeah, I dont know how AQuery behaves, but anyway you probably should only cache images while online.