How can I use Spring's ConfigurableEnvironment to reset a property value?

Question

New to Spring...

I am trying to override a parameter which is read from app.properties at runtime.

For various reasons, I have to use AnnotationConfigApplicationContext to access the bean.

Here is the sample code

@ComponentScan(basePackages = {
        "my.pkg1.*",
        "my.pkg2.*"
}    
@PropertySource("classpath:app.properties")
public class MainApplication {
    public static void main(String[] args) {
        try {
            log.info("ARGS [" + Arrays.asList(args).stream().collect(Collectors.joining()) + "]");    
            final AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MainApplication.class);
            ConfigurableEnvironment env =  context.getEnvironment();
            env.setRequiredProperties("prop1=value2"); //hard coded here for ease
            context.setEnvironment(env);
            context.getBean(MyService.class).doSomeWork();
        } catch (Exception t) { 
            log.error("Application failed", t);
        }
    }    
}

Let's say, in my app.properties, I have some thing like

prop1=value

I would like to override prop1=value2 but my approach as displayed above does not seem to work.

Couple of other things I looked at:

• I thought it would be as easy as: Spring: overriding one application.property from command line. But that did not work, maybe because this is not a spring-boot app?
• This other approach doesn't really work because I don't really want to pass a constructor param.
• I don't really understand this approach