Excample use a CommandLineRunner of Spring Boot

CommandLineRunnerDemo

@Configuration
public class AppConfig {
     //    @return Spring Boot {@link CommandLineRunner} automatically
     //          run after app context is loaded.
     @Bean
    public CommandLineRunner commandLineRunner(ApplicationContext ctx) {
            return args -> {
            System.out.println("Let's inspect the beans provided by Spring Boot:\n");
            String[] beanNames = ctx.getBeanDefinitionNames();
            Arrays.sort(beanNames);
            for (String beanName : beanNames) {
                System.out.println(beanName);
            }
            System.out.println("---");
        };
    }
//also supports:
//    @Bean
//    public CommandLineRunner commandLineRunner(TransactionServiceImpl transactionService) {
//        return args -> {
//            transactionService.init();
//            LOGGER.info("done");
//        };
//    }
}