How can I embed office 365 apps in a java based web application

We would like to offer all the capabilities that these apps offer to our customers for collaboration. From a developer perspective I understood that to integrate these apps in a third party web application we need to build custom UI’s and make calls to the Microsoft graph api underneath. While this solution does not have any roadblocks but it doesn’t sound worthwhile to implement a complete front-end for everything that these apps do.

I am curious to confirm if there is a better approach that would speed the time to market this integration task. Note that we are not looking at the approach of creating a custom app/tab inside office 365 that navigates to our web application. We would like our clients to access office 365 apps from within our application.