Properties for a Spring Boot App
There are, in fact, several ways to set properties for a Spring Boot application. Spring
Boot will draw properties from several property sources, including the following:
Command-line arguments
JNDI attributes from java:comp/env
JVM system properties
Operating system environment variables
Randomly generated values for properties prefixed with random.* (referenced when setting other properties, such as `${random.long})
An application.properties or application.yml file outside of the application
An application.properties or application.yml file packaged inside of the application
Property sources specified by @PropertySource
Default properties