The application I’m working on now uses Spring both by parsing for XML Spring configuration files in pre-determined locations and by scanning annotations-based autowiring. I’ve already stated my stance on autowiring previously, this article only concerns itself on how I could use Spring JavaConfig without migrating the whole existing codebase in a single big refactoring.
This is easily achieved by scanning the package where the JavaConfig class is located in the legacy Spring XML configuration file:
<ctx:component-scan base-package="ch.frankel.blog.spring.javaconfig.config" />However, we may need to inject beans created through the old methods into our new JavaConfig file. In order to achieve this, we need to autowire those beans into JavaConfig:
@Configuration
public class JavaConfig {
@Autowired
private FooDao fooDao;
@Autowired
private FooService fooService;
@Autowired
private BarService barService;
@Bean
public AnotherService anotherService() {
return new AnotherService(fooDao);
}
@Bean
public MyFacade myFacade() {
return new MyFacade(fooService, barService, anotherService());
}
}You can find complete sources for this article (including tests) in IDEA/Maven format.
Thanks to Josh Long and Gildas Cuisinier for the pointers on how to achieve this.