throw new DirectoryManagerConfigurationException("Index file " + filename + " does not exist");
log.logInfo("Index file '" + filename + "' does not exist");
    protected DirectoryManagerIndex readIndex() {        // Check if the index file exists.        File indexFile = new File(filename);        if (!indexFile.isFile())            throw new DirectoryManagerConfigurationException("Index file " + filename + " does not exist");        // Check if we have received a newer index file than the one previously        // read.        if (timestamp >= indexFile.lastModified())            return null; // No update necessary.        timestamp = indexFile.lastModified();        DirectoryManagerIndex index = null;        try {            // Read the new index from file.            ObjectInputStream in = new ObjectInputStream(new FileInputStream(filename));            index = (DirectoryManagerIndex) in.readObject();            in.close();        } catch (FileNotFoundException e) {            throw new DirectoryManagerConfigurationException("Index file " + filename + " does not exist");        } catch (IOException e) {            throw new DirectoryManagerConfigurationException("Unable to read index from file " + filename, e);        } catch (ClassNotFoundException e) {            throw new DirectoryManagerConfigurationException("Unable to instantiate index object", e);        }        timestamp = indexFile.lastModified();        return index;    }