Retrieving the servlet context path from a Spring web application

I would like to be able to dynamically retrieve the "servlet context path" (e.g. http://localhost/myapp or http://www.mysite.com) for my spring web application from a Service spring bean.

The reason for this is that I want to use this value in email that are going to be sent to users of the website.

While it would be pretty easy to do this from a Spring MVC controller, it is not so obvious to do this from a Service bean.

Can anyone please advise?

EDIT: Additional requirement:

I was wondering if there wasn't a way of retrieving the context path upon startup of the application and having it available for retrieval at all time by all my services?