Summary

In this chapter, we learned how to externalize parts of our system from content that appears in the web layer to the list of users allowed to authenticate with the system. We saw how to create type-safe configuration classes, bootstrap them from property files, and then inject them into parts of our application. We even saw how to use profile-based properties and choose between using traditional Java property files or using YAML. We then explored even more ways to override property settings from the command line and checked out a comprehensive list of yet more ways to override properties.

While our examples were probably not as realistic as they could have been, the concept is there. Externalizing properties that are likely to vary from environment to environment is a valuable feature, and Spring Boot eases the usage of this pattern.

In the next chapter, Releasing an Application with Spring Boot, we are finally going to release our application into the wild. There, we...