springannotationsaopspring-aopconfigurable

Configurable vs Component with Spring and AspectJ


When using AspectJ, why use @Component over @Configurable.

I've got Spring and AspectJ setup for @Transactional support, aspects on self-invocation, and injection into JPA entities. This works great.

I'm using @Component for most classes that need injection, and thus either having them injected into their dependencies. Or, when I can't, injecting the ApplicationContext and then using getBean() as a last resort. And I'm reserving @Configurable for only JPA entities (Hibernate) that need injection. I've also started using @Configurable for jUnit tests, to make writing tests easy. This also works great.

But I'm curious. If AspectJ is now auto-injecting (beanifying) anything with the @Configurable annotation, regardless of how its constructed; getBean(), new(), @Autowired. Why wouldn't I just switch to using @Configurable for all my beans? Then I can do away with the application context and getBean() altogether, and just new() any classes I can't inject.

I realize that I made no mention of XML bean configuration. I don't shy away from that, but this project doesn't happen to require any. I just constructor or setter inject the dependencies when testing. very easy.


Solution

  • One reason why you should not always use @Configurable is that it adds a lot of overhead: it often takes much longer for the app to start, and creating new instances becomes slower.

    For @Component you don't need it at all, because normally all the instances are managed by Spring.