soundshare | Rails application for uploading , playing and sharing audio | File Sharing library

So doing it yourself in code is not a good idea as mentioned by @Thomas Andolf, basically re-inventing the wheel. There are several methods for "externalising" your configurations.

https://docs.spring.io/spring-boot/docs/1.2.2.RELEASE/reference/html/boot-features-external-config.html

Personally I like using os environmental variables when I can because I can easily carry swap it when I deploy as containers as well.

This is a cross section of the application.properties file of a project I'm working on:

spring.datasource.url=${ospec_db_url} spring.datasource.username=${ospec_db_user:somedefault} spring.datasource.password=${ospec_db_password}

On my dev system, I just set the environmental variable and it gets picked up. In my case, I have a text file with my variables like this:

export ospec_db_url=jdbc:postgresql://localhost:5432/ospec_db
export ospec_db_password=somebadasspassword

I just source the text-file and it's applied. I can easily switch between projects doing this. When you package for say K8s, you can read from a secrets file to your env variable and when you go to the cloud, you can pass the values in as variables in your startup scripts.