java - Can I define System Properties within Spring Boot configuration files?

Question

I have a single application.yml configuration file for my Spring Boot app that defines two profiles (as described in the documentation).

When the production profile is enabled, I would like to set the http.maxConnections system property to a custom value, e.g.

spring:
    profiles:
        active: dev
---
spring:
    profiles: dev
---
spring:
    profiles: production
http:
    maxConnections: 15

But this doesn't actually set the system level property; it appears to just create an application-level property. I've verified this through both http://locahost:8080/env and a JMX Console when comparing launching by

java -jar -Dspring.profiles.active=production myapp.jar

versus

java -Dhttp.maxConnections=15 myapp.jar

I suppose I could create a bean that's @Conditional on the "production" profile that programmatically callsSystem.setProperty based on my application.yml-defined property, but is there a simpler way through configuration files alone?

Answer 1

You may try.

@Profile("production")
@Component
public class ProductionPropertySetter {

   @PostConstruct
   public void setProperty() {
      System.setProperty("http.maxConnections", "15");
   }

}