Possible to autowire imported utility classes in Spring?

Question

I want to use data mappers, logger, transfromers, etc. in my Spring web projects. Is it possible to autowire an imported (jar) utility dependency, without wrapping it in some @Component or @Service class? Do we even want to do it that way, or should we just use a static reference?

Answer 1

If your utils, are based on not static methods, then this is simple:

If you use java based configuration, then just declare that util in an @Bean annotated method.

@Configuration
public class YourConfig {

   @Bean 
   public YourUtil util(){
      return new YourUtil ();
   }
}

in xml it could been as simple as:

<bean id="util" class="org.example.YourUtil" />

---

The following is true, but it is not what was asked for:

There are at least two other ways to inject beans in instances that are not created (managed) by Spring:

• (1) add @Configurable annotation to this class - this requires real AspectJ (compile-time or load-time -weaving)

  • @see Spring Reference Chapter 7.8.1 Using AspectJ to dependency inject domain objects with Spring
  • @see this answer of mine https://stackoverflow.com/a/7007572/280244 for a quick "guide" to enable the @Configurable support

• (2) invoke SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this);

  • @see this question and its (two highes voted answers) for some ideas how to use

Answer 2

You can only @Autowire a bean managed by Spring. So you have to declare your instance through some configuration : a bean in an xml file, or a @Bean method in a java configuration.

@Component are just automatically discovered and registered in the spring context.