Load nested yaml properties using spring-boot - spring-boot

Question

I have the following application-errors.yml file defined in src/main/resources of my Java spring-boot application:
client:
badrequest: {code: 001, message: 'Malformed request', status: 400}
configuration: {code: 002, message: 'Invalid EC2 VPC configuration', status: 400}
server:
unexpected.error:
code: 004
message: 'Unexpected error occurred. Please try again'
status: 500
Note that I've tried two different formats for specifying the properties.
I load that property file via the following Bean from a #Configuration annotated class:
#Bean
public static YamlPropertiesFactoryBean getYamlProperties() {
YamlPropertiesFactoryBean yaml = new YamlPropertiesFactoryBean();
yaml.setResources(new ClassPathResource("application-errors.yml"));
return yaml;
}
I see that the properties are loaded via the Spring Environment variable, but not in the pattern that I would expect. When debugging through, I can see that the source of the loaded property file contains the following values:
{client.badrequest=code:001 message:'Malformed request' status:400, client.configuration=code:002 message:'Invalid EC2 VPC configuration' status:400, server.unexpected.error=code:004 message:'Unexpected error occurred. Please try again' status:500}
It looks like the yaml file was flattened partially (only two levels deep). Instead, I was expecting each end property to be flattened on its own. The format that I was expecting would have been something like this:
{client.badrequest.code=001, client.badrequest.message='Malformed request', client.badrequest.status=400, client.configuration.code=002, client.configuration.message='Invalid EC2 VPC configuration', client.configuration.status=400, server.unexpected.error.code=004, server.unexpected.error.message='Unexpected error occurred. Please try again', server.unexpected.error.status=500}
What do I need to change in order to ensure Spring flattens the properties the entire way? If I'm not understanding either yaml formatting patterns or the pattern that Spring follows to flatten yaml files correctly, please correct my understanding.

Answer 1

I've found the multiple errors I made when arriving at this question this morning:
1) My code was not actually loading any custom named yml property files. Instead, it was picking up the default application.yml file that I also had in my project.
2) That default application.yml file had yml formatted code with the wrong syntax. Specifically, I had omitted the required space after each property identifier:
client:
badrequest:
code:001
message:'Malformed request'
status:400
configuration
code:002
message:'Invalid EC2 VPC configuration'
status:400
server:
unexpected.error
code:004
message:'Unexpected error occurred. Please try again'
status:500
After understanding those two issues, I was able to correctly load properties from application.yml.
The final syntax I landed on for my properties is the following:
# Error Properties
client:
badrequest: {code: 001, message: 'Malformed request', status: 400}
configuration: {code: 002, message: 'Invalid EC2 VPC configuration', status: 400}
server:
unexpected.error: {code: 004, message: 'Unexpected error occurred. Please try again', status: 500}