SPRING CONCEPTS
Environment variables
Spring Concepts / Environment variables
Environment variables supply configuration to a running process.
Understand the idea
Spring property placeholders read deployment values from the environment. A terminal assignment applies to that terminal and its child processes. An IDE run configuration needs its own launch environment. Keep secrets out of checked-in files and browser code.
A concrete example
spring.mongodb.uri=${MONGODB_URI}
app.jwt.secret=${JWT_SECRET}In the application
MONGODB_URI configures Atlas for all backends; JWT_SECRET supplies the personal API signing key.
Spring does not automatically load an arbitrary .env file. Variables set in one terminal do not automatically reach an already-running IDE.