@SpringBootApplication
public class DemoApplication {

    @Bean
    public static HelloWorld getMessageBean(){
        HelloWorld hw = new HelloWorld();
        hw.setMessage("Hello World!");
        return hw;
    }

    public static void main(String[] args) {
        SpringApplication.run(DemoApplication.class, args);
        System.out.println("Message: " + getMessageBean().getMessage());
    }
}