Aspect Configuration

Same as any other Java Pojo class, the Aspect annotated class also can be used as given below
@Bean
public Passenger passenger() {
  return new Passenger();
}

By using the @EnableAspectJAutoProxy  we can turn the proxy on in Java based Configuration
@Configuration
@EnableAspectJAutoProxy
@ComponentScan

public class FlightConfig {
   @Bean
   public Passenger passenger() {
       return new Passenger ();
   }
}

If you will not annotate the class with the  @EnableAspectJAutoProxy then your class Passenger
will be a simple pojo class only. It won't be Aspect.

In XML based configuration add below line for turning on the proxy
<aop:aspectj-autoproxy />