Let's see the following order of evaluation for overridden properties:

1. Defined properties for the Devtools global settings in your home directory
2. Defined properties for @TestPropertySource annotations on your tests
3. Properties as command-line arguments
4. Defined properties from SPRING_APPLICATION_JSON
5. The properties with ServletConfig init parameters
6. The properties with ServletContext init parameters
7. JNDI attributes from java:comp/env
8. Java system properties
9. OS environment variables
10. Property file(s)—including application.properties and its YAML variant

This preceding list is in order of precedence. That means if you set any property from a source higher in the list, Spring will override the same property defined in the source lower in the list. The test environment and command-line arguments override properties from any other property source.

Let's see the following order of evolution of the properties file and YAML variants:

1. A RandomValuePropertySource class that injects properties with random value into configuration file define as random.*
2. Profile-specific application properties outside of your packaged JAR, that is, in the /config subdirectory of the directory from which the application is run (application-{profile}.properties and YAML variants)

3. Profile-specific application properties outside of your packaged JAR but in a directory from which the application is run (application-{profile}.properties and YAML variants)
4. Profile-specific application properties packaged inside your JAR but in a package named config (application-{profile}.properties and YAML variants)
5. Profile-specific application properties packaged inside your JAR but at the root of the classpath (application-{profile}.properties and YAML variants)
6. Application properties outside of your packaged JAR, that is, in the /config subdirectory of the directory from which the application is run (application.properties and YAML variants)
7. Application properties outside of your packaged JAR but in a directory from which the application is run (application.properties and YAML variants)

8. Application properties packaged inside your JAR but in a package named config (application.properties and YAML variants)
9. Application properties packaged inside your JAR but at the root of the classpath (application.properties and YAML variants)
10. @PropertySource annotations on your @Configuration classes
11. Default properties (specified using SpringApplication.setDefaultProperties)

According to the order of precedence, if you set any properties in a profile-specific application-{profile}.properties will override the same properties set in an application.properties file at the same location as the application-{profile}.properties file.

Again, this list is in order of precedence. That is, an application.properties file in a /config subdirectory will override the same properties set in a application.properties file in the application's classpath.

Let's see how to customize the name of the application property file (application.properties).