private final String loadFile(final String filename) {
        if (filename == null)
            return null;
        
        final File file = new File(filename);
        final char[] data = new char[(int)file.length()];
        try {
            final FileReader reader = new FileReader(file);
            if (reader.read(data) != data.length)
                System.err.println("???");
            reader.close();
            return String.valueOf(data);
        } catch (FileNotFoundException ex) {
            ex.printStackTrace();
        } catch (IOException ex) {
            ex.printStackTrace();
        }
        return null;
    }