spring – Approach to build a modularity Java (Web) Application

I’m on the way to build a modular Java web project with some pluggable modules – like Jira and Confluence for example.
My first thought was to build a project with Spring and OSGi, I started finding a workable OSGi framework that can suit Spring. It led me to Spring Dynamic Module (SDM) and Gemini Blueprint (GB). SDM is dead and GB is not popular – I even can’t find any tutorials (work with Spring). I’m thinking of an alternative way but I don’t have much experience in this area. Does anyone have any suggestions for my project? We can leave OSGi, even Spring behind.
Any helps is appreciated.

Thank you.