How to access configuration beans in Spring controllers

I have a Spring Boot application that uses Spring profiles to create environment specific configurations, for example:

@Configuration
@Profile("local")
public class LocalConfiguration
...

@Configuration
@Profile("prod")
public class ProdConfiguration
...

I have a @RestContoller that needs to access the values that the configurations load from application.properties. How can I inject the current environment specific configuration bean inside the controller?

Example:

@Autowired
private <config_based_on_env_here> config;

@RestController
public String getSomeString() {
    return config.getSomeString();
}

Answer

If you need to access values from the application.properties or .yaml configuration you could use a much simpler way for achieving this.

Firstly configure different configs:

application-local.properties

my.value=local-value

application-prod.properties

my.value=prod-value

Create a configuration for reading needed value:

@Configuration
@ConfigurationProperties(prefix = "my")
public class ConfigProperties {
    
    private String value;

    // standard getters and setters
}

Finally, you could autowire this configuration at the controller:

@RestController
class MyController {

    @Autowire
    private ConfigProperties config;

    @GetMapping("/hello")
    public void hello() {
      System.out.println("Config value: " + config.getValue()); 
    }
}

When you run your app with the needed profile – the appropriate config file will be loaded and accessed at the controller.

Also, you could have a look at @Value annotation

Additional resources:

• Externalized Configuration
• Configuration properties in Spring
• A Quick Guide to Spring @Value