How to use spring @autowired annotation in the class having void methods?

Question

I have an interface and service implements it. It has some void methods. I am using spring java bean configuration. But unable to create bean object because of void methods.How to handle this problem.

I tried to use @PostConstruct instead of @Bean after reading some blogs, but it didn't work out.

public interface MyInterface {
  void someData(List<MyClass> list, String somedata);
}

@Service("myInterface")
public DummyClass implements MyInterface {

   public  void someData(List<MyClass> list, String somedata){
       // my business logic 
   }
}

public AppConfig {
 @Bean
 public MyInterface  myInterface {
    return new DummyClass();  // but gives error void cannot return value
  } 
}

My Junit looks like this

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(
  classes = {AppConfig.class}, 
  loader = AnnotationConfigContextLoader.class
)

public class MyTest {

  @Autowired
  DummyClass dummyClass;

  // If I don't use AppConfig and simply autowire then I get 
  "Error creating bean name, unsatisfied dependency
}

How do I achieve dependency injection here?

Answer 1

1. Use @Configuration annotation on AppConfig class, with this all the beans defined on this class will be loaded on spring context.

2. If you use @Service annotation on DummyClass, you do not need to declare @Bean annotation because you are already saying to spring to detect this class for dependency injection. On the other hand use @Bean annotation to specify the instantiation of the class. Normally I let the @Bean to complex classes for dependency injection or to override configurations.