[FIXED] Declare list of objects in Spring application.properties file

Issue

In a Spring Boot application, I would like to be able to declare a list of my domain objects in my application.properties file and read them as a List<TheDomainObject> as a Bean.

For example, let's say I have the following in application.properties:

com.application.person.john.name=John Smith
com.application.person.john.home-directory=/Users/john.smith
com.application.person.john.private-key-file=/Users/john.smith/.ssh/id_rsa

com.application.person.adam.name=Adam Bell
com.application.person.adam.home-directory=/Users/adam.bell
com.application.person.adam.private-key-file=/Users/adam.bell/.ssh/id_rsa

etc

I.e. I'd like to have properties for each person grouped under a key. I'd be able to add as many keys (people) as I like.

I would not need to reference these properties directly, but I'd like to declare a Domain object as follows (abbreviated):

class Person {
  String id;   (this would be the 'key', i.e. 'john', 'adam')
  String name;
  Path homeDirectory;
  Path privateKeyFile;

  // boilerplate
}

and then receive a List<Person> through Configuration. The more automatic the better, but I would be more than happy to implement builders or some additional converter logic if needed.

I can't find any documentation for this kind of thing, but I have seen it in log4j for example, where you can dynamically add logging properties for any package name, so it must be possible to at least retrieve those keys.

I know I can do this differently, for example by using a data.sql import script, however in my case it would be very ideal to have this in a single properties file (or yaml) format.

Solution

Why don't you use id as an explicit property?

for example (yaml):

com:
  application:
    persons:
      - 
        id: john
        name: John Smith
        home-directory: /Users/john.smith
      - 
        id: adam 
        name: Adam Bell
        home-directory: /Users/adam.bell

This would resolve in List<Person> persons;

Answered By - JavaBoy
Answer Checked By - Senaida (JavaFixing Volunteer)