title: How to achieve highest possible compression on an Excel file using Java
body: <p>I have a system generated excel file (around 40-50 MB or more of size). I have to zip the file and send it over email. Currently I am using  Java 7 ZipOutputStream api to achieve the same (using Deflater.BEST_COMPRESSION option). I also explored GZIPOutputStream api.
  The results are OK, but I was wondering if there are any other APIs or third party libraries which can help achieve even better compression ratio and help reduce the compressed file size further. I am not bothered about how much time is taken to compress the file, or extract the file.</p>