Multiple profiles inside a single YAML file

A YAML file can contain configuration for multiple profiles. You can define multiple profile-specific configurations in a single YAML file. Spring Boot provides a spring.profiles key to indicate when the document applies. Let's see the following example of how to define multiple profile-specific configurations in a single YAML file:

 
#Used for all profiles 
 
logging.level: 
org.springframework: INFO 
 
#'dev' profile only 
--- 
 
spring.profiles: dev 
database: 
   host: localhost 
   user: dev 
 
#'prod' profile only 
 
--- 
 
spring.profiles: prod 
database: 
   host: 192.168.200.109 
   user: admin 

In this application.yml file, we have defined database settings according to two profiles, dev and prod, by using a spring.profile key. In the file, '---' implies a separation between profiles.

Also, I've found that if you have both application.properties and application.yml side by side at the same level of precedence, properties in application.yml will override those in application.properties.

Let's see how to customize the error page in the Spring web application.