How can I explicitly define an order in which Spring's out-of-the-box process of reading properties out of an available-in-classpath application.yml

How can I explicitly define an order in which Spring's out-of-the-box process of reading properties out of an available-in-classpath application.yml will take place BEFORE my @Configuration annotated class which reads configuration data from zookeeper and places them as system properties which are later easily read and injected into members using @Value?

I have a @Configuration class, which defines a creation of a @Bean, in a which configuration data from zookeeper is read and placed as system properties, in a way that they can easily be read and injected into members using @Value.

@Profile("prod")
@Configuration
public class ZookeeperConfigurationReader {

    @Value("${zookeeper.url}")
    static String zkUrl;

    @Bean
    public static PropertySourcesPlaceholderConfigurer zkPropertySourcesPlaceHolderConfigurer() {
        PropertySourcesConfigurerAdapter propertiesAdapter = new PropertySourcesConfigurerAdapter();
        new ConfigurationBuilder().populateAdapterWithDataFromZk(propertiesAdapter);
        return propertiesAdapter.getConfigurer();
    }

    public void populateAdapterWithDataFromZk(ConfigurerAdapter ca) {
      ...
    }

}

Right now I pass the zookeeper.url into the executed program using a -Dzookeeper.url which is added to the execution line. Right now I read it by calling directly System.getProperty("zookeeper.url").

Since I'm using Spring-Boot application, I also have a application.yml configuration file.

I would like to be able to set the zookeeper.url in the application.yml, and keep my execution line clean as possible from explicit properties.

The mission turns out to be harder than I thought.

As you can see in the above code sniplet of ZookeeperConfigurationReader, I'm trying to inject that value using @Value("${zookeeper.url}") into a member in the class which performs the actual read of data from zookeeper, but at the time the code that needs that value accesses it, it is still null. The reason for that is that in spring life cycle wise, I'm still in the phase of "configuration" as I'm a @Configuration annotated class myself, and the spring's code which reads the application.yml data and places them as system properties, hasn't been executed yet.

So bottom line, what I'm looking for is a way to control the order and tell spring to first read application.yml into system properties, and then load ZookeeperConfigurationReader class.