BeanIOFlatFileItemWriter - FooterCallback compatibility

[adrianodsq]

The class BeanIOFlatFileItemWriter already have a FlatFileHeaderCallback attribute, but don't have a FlatFileFooterCallback.
It would be great if it was possible to use it too, just like FlatFileItemWriter.

I guess that all it takes is to implement the usage on the "close()". Since all the attributes are private and inner classes, it cannot be extended or overrided to have acess to Stream.

public void close() throws ItemStreamException {
        if (stream != null) {
            try {
                if (footerCallback != null && stream.writer != null) {
                    footerCallback.writeFooter(stream.writer);
                    stream.writer.flush();
                }
            } catch (IOException e) {
                throw new ItemStreamException("Failed to write footer before closing", e);
            } finally {
                stream.close();
                stream = null;
            }
        }
    }

Thanks for the great lib!