I want to enforce HTTPS for a Spring Boot application to be hosted at Pivotal CloudFoundry, and I think most of the applications would want this today. The common way of doi
Normally, when you push a WAR file to Cloud Foundry, the Java build pack will take that and deploy it to Tomcat. This works great because the Java build pack can configure Tomcat for you and automatically include a RemoteIpValve, which is what takes the x-forwarded-* headers and reconfigures your request object.
If you're using Spring Boot and pushing as a JAR file, you'll have an embed Tomcat in your application. Because Tomcat is embedded in your app, the Java build pack cannot configure it for the environment (i.e. it cannot configure the RemoteIpValve). This means you need to configure it. Instructions for doing that with Spring Boot can be found here.
If you're deploying an web application as a JAR file but using a different framework or embedded container, you'll need to look up the docs for your framework / container and see if it has automatic handling of the x-forwarded-* headers. If not, you'll need to manually handle that, like the other answers suggest.