Spring Boot and multiple external configuration files

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UPDATE:
As the behaviour of spring.config.location now overrides the default instead of adding to it. You need to use spring.config.additional-location to keep the defaults. This is a change in behaviour from 1.x to 2.x

When using Spring Boot the properties are loaded in the following order (see Externalized Configuration in the Spring Boot reference guide).

  1. Command line arguments.
  2. Java System properties (System.getProperties()).
  3. OS environment variables.
  4. JNDI attributes from java:comp/env
  5. A RandomValuePropertySource that only has properties in random.*.
  6. Application properties outside of your packaged jar (application.properties including YAML and profile variants).
  7. Application properties packaged inside your jar (application.properties including YAML and profile variants).
  8. @PropertySource annotations on your @Configuration classes.
  9. Default properties (specified using SpringApplication.setDefaultProperties).

When resolving properties (i.e. @Value("${myprop}") resolving is done in the reverse order (so starting with 9).

To add different files you can use the spring.config.location properties which takes a comma separated list of property files or file location (directories).

-Dspring.config.location=your/config/dir/

The one above will add a directory which will be consulted for application.properties files.

-Dspring.config.location=classpath:job1.properties,classpath:job2.properties

This will add the 2 properties file to the files that are loaded.

The default configuration files and locations are loaded before the additonally specified spring.config.location ones meaning that the latter will always override properties set in the earlier ones. (See also this section of the Spring Boot Reference Guide).

If spring.config.location contains directories (as opposed to files) they should end in / (and will be appended with the names generated from spring.config.name before being loaded). The default search path classpath:,classpath:/config,file:,file:config/ is always used, irrespective of the value of spring.config.location. In that way you can set up default values for your application in application.properties (or whatever other basename you choose with spring.config.name) and override it at runtime with a different file, keeping the defaults.

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