public boolean ensureFolder(final PersistableFolder publicFolder) {
        final Folder folder = getFolder(publicFolder, false);
        if (folder == null) {
            return false;
        }
        return ensureFolder(folder, publicFolder.needsWrite(), false);
    }
checks if folder is available and can be used, creates it if need be.
main/src/main/java/cgeo/geocaching/storage/ContentStorage.java