Ultimately the portal is a collection of these siloed applications. Also, there maybe be only a few Spring based webapps that house multiple of these types of applications. For example, you may have a personal information set of Spring controllers in a Java package and html content in portal-web-app and then the help and feedback application is in the portal-web-app, etc.
I was looking to redesign using angularjs, reactjs, vuejs, or just jquery for front-end but don't see where it might aid in an application that supports multiple page apps or an application that still may require Spring MVC to render some of the content on the server side.
We could use just jQuery and connect to Spring MVC based REST services and receive the benefit of Ajax based application. This approach also allows us to support multi-page applications where some of the HTML content may be completely rendered by Spring MVC. There is more flexibility with this approach but jQuery seems too lightweight. For example, it seems easier and less buggy to build up a single view in AngularJS than with jQuery. It would be nice if I could get the directives from AngularJS without the requirement of having to build a Single Page app.