title: Finding your application's URL with only a ServletContext
body: <p>I'm writing a Java web app using Spring MVC. I have a background process that goes through the database and finds notifications that must be e-mailed to my users. These e-mail messages need to include hyperlinks to the application. This seems like a fairly common pattern for a web app, but I'm having trouble.</p>
  
  <p>How do I derive my application's fully qualified URL, with server name and context path? I don't have access to any of the methods in HttpServletRequest because I'm running this as a background process, not in response to a web request. The best I can do is get access to ServletContext.</p>
  
  <p>Currently I'm putting the base URL into a configuration file and reading it at startup, but this application is going to be licensed and deployed to customers' application servers, and if possible I'd like them not to have to configure this manually.</p>