spring autowired aop circular dependency

Question

I'm using java config with @ComponentScanin order to initialize my beans and @EnableAspectJAutoProxy(proxyTargetClass=true)to use cglib proxies.

In this project we have a lots of generated services autowired between them using @Autowired. It works pretty well.

But, for some of these services I've added @Async (I've also added @EnableAsync(proxyTargetClass = true)on my @Configurationclass).

After that, I'm getting:

Caused by: org.springframework.beans.factory.BeanCurrentlyInCreationException: Error creating bean with name 'ConversationUserLocalService': Bean with name 'ConversationUserLocalService' has been injected into other beans [ConversationUserHistoryLocalService] i
n its raw version as part of a circular reference, but has eventually been wrapped. This means that said other beans do not use the final version of the bean. This is often the result of over-eager type matching - consider using 'getBeanNamesOfType' with the 'a
llowEagerInit' flag turned off, for example.

I guess this is because Spring is injecting the service with @Asyncmethod BEFORE AOP creates the proxy. Could this be the problem? How I should fix it?

In order to try to clarify my problem, let's say I have:

@Service A, B & C;

A has autowired B & C, B has autowired A & C, C has autowired A & B;

C has a method marked as @Async.

When Spring initialize applicationContext, it tries to initialize A, but needs B & C, so it initializes them. But after all, AOP tries to make a proxy of C (because @Async) and then it detects that autowired C into B and A is not the same as proxy of C so it fails.

I hope this can explain a little more what is happening.

Barnes

Please post a SSCCE – Wilona

Answer 1

AsyncConfigurer configuration classes get initialized early in the application context bootstrap. If you need any dependencies on other beans there, make sure to declare them @Lazy as far as possible in order to let them go through other post-processors as well.

Reference JavaDoc: https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/scheduling/annotation/EnableAsync.html

Elveraelves

Answer 2

Finally I sorted it out using @Lazyon services (with methods annotated with @Async), and also, where they were autowired. This way I guess Spring only initialize and autowires those services when they're required instead of on application context initialization.

Barnes

Hey, can you explain on the part : "it detects that autowired C into B and A is not the same as proxy of C" – Saville

When Spring creates a proxy to add async behavior into C it doesn't updates references on A and B. So both of them has a reference to the raw version of C. – Barnes

thanks for the explanation. just one more thing, will this depend on the order in which spring initializes the services. In your example, if spring initialized C first even then the same exception will occur? – Saville

So @Lazy @Autowired the service into the other services got me the wanted result. – Grubb

Answer 3

I had same issue and I solved this issue:

1. I identified which @Autowired property is reason for circular dependency.

   Eg:

   @Autowired
   private TestService testService;
   

   (Tips to identified just try to comment and find out which property is reason to break the application)

2. Once identified just use @Lazy on top of this @Autowired variable.

   Eg :

   @Lazy
   @Autowired
   private TestService testService;
   

   And Application worked smoothly.

Dulosis

Answer 4

For me, it was impossible to add @Lazy above all existing @Autowires of an existing Service, as they were more than 100. So, by creating a new Service, moving there all methods requiring @Async decorator, and then Autowiring this new Service when needed (without @Lazy), works perfectly.

Rakeoff