Can I Autowire a Bean? - spring

Question

I am trying to understand Spring/Spring-boot. My question is, can I use a Bean instantiated/declaired by #Bean to a #Autowired field? Below is my classes, what i have defined.
#SpringBootApplication
public class SpringBootTestApplication {
#Bean(name = "TestServiceInterfaceImplBean")
TestServiceInterface getTestService() {
return new TestServiceInterfaceImpl();
}
#Autowired
public ServiceCaller serviceCaller;
public static void main(String[] args) {
ApplicationContext appContext = new
AnnotationConfigApplicationContext(SpringBootTestApplication.class);
Arrays.asList(appContext.getBeanDefinitionNames()).forEach(beanName ->
System.out.println(beanName));
SpringApplication.run(SpringBootTestApplication.class, args);
}
}
#Component()
public class ServiceCaller {
#Autowired
#Qualifier(value = "TestServiceInterfaceImplBean")
TestServiceInterface testService;
public ServiceCaller(){
System.out.println("############################### ServiceCaller");
}
}
//Service Interface
public interface TestServiceInterface {}
//Interface Implementation Class
public class TestServiceInterfaceImpl implements TestServiceInterface {
public TestServiceInterfaceImpl() {
System.out.println("############################### TestServiceInterfaceImpl");
}
}
I know by tagging #Service/#Component to TestServiceInterfaceImpl and removing #Bean and the method getTestService(), i can have #Autowire successful but i am just tyring to understand whether i can Autowire a Bean?
In this case i am getting below exception. By looking at the exception i am not able to understand where and how the loop is created.
Exception:
Description:
The dependencies of some of the beans in the application context form a cycle:
┌─────┐
| springBootTestApplication (field public com.SpringBootTestApplication.service.ServiceCaller com.SpringBootTestApplication.SpringBootTestApplication.serviceCaller)
↑ ↓
| serviceCaller (field com.SpringBootTestApplication.service.TestServiceInterface com.SpringBootTestApplication.service.ServiceCaller.testService)
└─────┘
Action:
Relying upon circular references is discouraged and they are prohibited by default. Update your application to remove the dependency cycle between beans. As a last resort, it may be possible to break the cycle automatically by setting spring.main.allow-circular-references to true.

Answer 1

You'd better move below part to a Configuration (#Configuration) class:
#Bean(name = "TestServiceInterfaceImplBean")
TestServiceInterface getTestService() {
return new TestServiceInterfaceImpl();
}
#Autowired
public ServiceCaller serviceCaller;
then do the test again. And another point, for ServiceCaller, you can even define its order after the Bean of TestServiceInterfaceImplBean created.
the 2 configuration class like:
#Configuration
#AutoConfigureAfter({ MyConfiguration2.class })
public class MyConfiguration {
public MyConfiguration() {
}
#Autowired
public ServiceCaller serviceCaller;
}
#Configuration
public class MyConfiguration2 {
public MyConfiguration2() {
}
#Bean(name = "TestServiceInterfaceImplBean")
public TestServiceInterface getTestService() {
return new TestServiceInterfaceImpl();
}
}