// mimetype
        putResultDataBody(dataMap, fessConfig.getIndexFieldMimetype(), mimeType);
        if (fileTypeHelper != null) {
            // filetype
            putResultDataBody(dataMap, fessConfig.getIndexFieldFiletype(), fileTypeHelper.get(mimeType));
        }
        // content_length
        putResultDataBody(dataMap, fessConfig.getIndexFieldContentLength(), Long.toString(responseData.getContentLength()));

        // mimetype
        putResultDataBody(dataMap, fessConfig.getIndexFieldMimetype(), mimeType);
        if (fileTypeHelper != null) {
            // filetype
            putResultDataBody(dataMap, fessConfig.getIndexFieldFiletype(), fileTypeHelper.get(mimeType));
        }
        // content_length
        putResultDataBody(dataMap, fessConfig.getIndexFieldContentLength(), Long.toString(responseData.getContentLength()));

     * The value is, e.g. filetype <br>
     * comment: Field name for file type in the index.
     * @return The value of found property. (NotNull: if not found, exception but basically no way)
     */
    String getIndexFieldFiletype();

    /**
     * Get the value for the key 'index.field.filename'. <br>
     * The value is, e.g. filename <br>
     * comment: Field name for file name in the index.