StringDiskLruCache based on Jake Warthon's DiskLruCache

gistfile1.txt

public class StringDiskLruCache {

    private static final int EXPIRATION = 1000 * 60 * 60 * 24;
    private static final int DATA_INDEX = 0;
    private static final int EXPIRATION_INDEX = 1;
    private static final int INDEXES_COUNT = 2;

    private Context context;
    private DiskLruCache cache;

    @Inject
    public StringDiskLruCache(App app) {
        this.context = app;
        open(context);
    }

    private void open(Context context) {
        try {
            File dir = new File(context.getCacheDir(), getClass().getSimpleName());
            int versionCode = context.getPackageManager().getPackageInfo(context.getPackageName(), 0).versionCode;
            cache = DiskLruCache.open(dir, versionCode, INDEXES_COUNT, 3 * 1024 * 1024);
        }
        catch (Exception e) {
            printException(e);
        }
    }

    public void remove(String key) {
        try {
            cache.remove(key);
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }

    public void put(String key, String value) {
        try {
            DiskLruCache.Editor editor = cache.edit(key);
            editor.set(DATA_INDEX, value);
            editor.set(EXPIRATION_INDEX, "" + (System.currentTimeMillis() + EXPIRATION));
            editor.commit();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
    }

    public String get(String key) {
        try {
            DiskLruCache.Snapshot entry = cache.get(key);
            if (entry != null)
                return entry.getString(DATA_INDEX);
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    public boolean isValid(String key) {
        try {
            DiskLruCache.Snapshot entry = cache.get(key);
            return entry != null && Long.parseLong(entry.getString(EXPIRATION_INDEX)) < System.currentTimeMillis();
        }
        catch (Exception e) {
            e.printStackTrace();
        }
        return false;
    }

    public void invalidate() {
        try {
            cache.delete();
        }
        catch (IOException e) {
            e.printStackTrace();
        }

        open(context);
    }
}