I have a spring boot application and I want to use both a yml file for my application properties and also a plain application-${profile}.properties file set to configure my application. 

So my question is can this be done and if so, how do you configure spring boot to look for both the yml file and the properties and merge them into one set per environment?

As to why I want/need to use both, it is because I like the flexibility and ease of use of yml files but an internal component (for encryption) requires using the properties file set. 

I did see this point being made [YAML files can’t be loaded via the @PropertySource annotation](http://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-external-config-yaml-shortcomings)

but nothing stating whether both can be used together. 

Please provide detailed configuration (XML or Java config) on how to get this working.

TIA,

Scott