Getting The Protocol From A Java Cloud Foundry App

How to identify the protocol in a Cloud Foundry Java application

Sometimes you need to invoke other files in your Java Cloud Foundry application (make AJAX calls or load JavaScript). If your app is working through HTTPS, and you try to have the browser load another file through HTTP, it will break. So a good practice is to try to identify which protocol is being used and form the links accordingly.

You usually have access to the Request object and that has a method called getProtocol(). In traditional web application server deployments, that is all you need. Parse that string and you’re done. But in Cloud Foundry, because there is a load balancer in front of your instances, that method always returns "HTTP/1.1".

To overcome that problem, Cloud Foundry inserts a header called “x-forwarded-proto”. All you need to do is use the request.getHeader(“x-forwarded-proto”) method and use the returned value. It will either be http or https.