Reloading a Commons Configuration 2 Spring bean

Question

I've been using the reload feature of Commons Configuration v1 without any extra coding when exposing a Configuration object as a Spring @Bean, because the reload check was performed every time the Configuration was accessed.

I'm now trying to migrate to Commons Configuration v2 and I read that reload is only effective on new Configuration objects created by the builder.

In other words, while in v1 I could do something like

@Bean
public Configuration config() {
    ...
    return builder.getConfiguration();
}

then inject the configuration with

@Autowired Configuration config;

and expect it to reload (when needed) on a

config.getString("somepath");

now I should call

builder.getConfiguration()

again each time I want a fresh configuration.

So how do I go about it? Can anything in Spring help me "refresh" a @Bean that has already been injected in many @Controllers? It doesn't have to be automatic: I could implement a "reload" button in the admin console to trigger it.

Look at Spring Cloud Config. They've implemented reloading there and it works well. If you dig into how they've integrated with Spring you may be able to re-use it. About 6 months ago I did a POC where I got it working with JSON we pull from a config server. — kab, Jun 01 '16 at 21:48
Thank you for the suggestion but, for the time being, Spring Config seems to be overkill for what I need to do. — xtian, Jun 02 '16 at 13:59

xtian · Answer 1 · 2016-06-06T12:37:40.193

Maybe I just have to wrap the Configuration in a MyConfiguration class, exposed as a @Bean, with a method that rebuilds the configuration, to be called from a console. Something like:

public class MyConfiguration {
    private Configuration configuration;

    ... inject builder somehow here

    public void reload() {
        builder.getReloadingController().checkForReloading(null);
        configuration = builder.getConfiguration();
    }

    public String getString(String key) {
        return configuration.getString(key);
    }

    ... all other delegated methods follow

}

Reloading a Commons Configuration 2 Spring bean

1 Answers1