如何根据参数创建spring boot bean

Question

I have a custom (non-spring) command line processing and i want to create some spring beans configured using that computed parameters

fun main(args: Array<String>) {
        val computed = processArgs(args)
        if (computed.xxx()) {
           runApplication<Main>(*args) // run spring app
        } else {
          do_something_without_spring(computed)
        }
}

and then i want to have a bean factory that depends on computed

@Configuration
class Config {
 
   @Bean
   fun createBean() {
      if (computed.xyz()) ...  // how to pass `computed` here? 
   }
}

how should i pass it? just encode it as string and add to args? how to access it later in factory method? or is there any way to inject bean into spring context?

Answer 1

You can autowire ApplicationArguments bean to read the application arguments that were passed to SpringApplication.run(…​)

See: https://docs.spring.io/spring-boot/docs/current/reference/html/spring-boot-features.html#boot-features-application-arguments

Example:

@SpringBootApplication
public class DemoApplication {
    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
    }
}

@Configuration
class C {
    @Bean
    B b(ApplicationArguments args) {
        System.out.println(String.join("", args.getSourceArgs()));
        return new B();
    }
}
class B { }