Spring Boot 4 cheatsheet
Spring Boot 4: Configuration
5 common Spring Boot 4 tasks.
Run with a profile
Activate application-prod.properties for one run.
java -jar app.jar --spring.profiles.active=prod
Set a profile with an environment variable
Environment variables override properties, which suits containers.
SPRING_PROFILES_ACTIVE=prod java -jar app.jar
Bind properties to a class
Map properties with the prefix app to a typed class.
@ConfigurationProperties(prefix = "app")
public record AppProperties(String name, int timeout) {}
Configure a database
Point the app at PostgreSQL. Use real credentials from the environment.
spring.datasource.url=jdbc:postgresql://localhost:5432/mydb
spring.datasource.username=${DB_USER}
spring.datasource.password=${DB_PASSWORD}