External Configuration

Spring Boot framework allows application developers to run the same Spring Boot application in different environments by making use of its feature of external configuration.

The configuration in Spring Boot application uses environment variables, properties files, command-line arguments, YAML files, and system properties to mention the required configuration properties for its corresponding environments.

Possible sources of external configuration in Spring Boot applications can be done in the following ways:

Command-line properties

Spring Boot provides support for command-line arguments and converts these arguments to properties and then adds them to the set of environment properties.

Application Properties

By default, Spring Boot searches for the application properties file or its YAML file in the current directory of the application, classpath root, or config directory to load the properties.

Profile-specific properties

Properties are loaded from the application-{profile}.properties file or its YAML file. This file resides in the same location as that of the non-specific property files and the {profile} placeholder refers to an active profile or an environment.