Thanks for getting in touch! Generally in Octopus, we follow the idea that if you can package it, we can deploy it. So if you are able to zip your .war file, then Octopus can deploy it and run scripts to do anything else needed.
Thanks for getting back! As far as actually deploying the .war file to your server, there are a couple of resources that I can provide you. You may have already seen this but there is a documentation page on deploying java applications on our website. https://octopus.com/docs/guides/deploying-java-applications
Currently we do not have too much in the way of direct support/documentation for deploying java applications. However, we are currently looking into improving this. If you gave any more specific questions on areas you are stuck with regarding your deployment, please feel free to let me know and ill do my best to help. :)