StackOverflowError: recursive proxy creates a stack overflow when creating a custom `ClientDetailsService` component

[joshlong]

please see https://github.com/joshlong/authscratch.

this example provides a custom ClientDetailsServcie. Ive defined it twice, one using a @Bean provider method, and again as a @Service. the @Bean works, but the @Service doesnt. Comment out either @Service or @Bean to test.

[dsyer]

The app starts up fine for me with either the @Bean ClientDetailsService or the @Service (JpaClientDetailsService). Maybe you changed something? Assuming all is OK, and closing.

[dsyer]

Sorry, I don't think I knew how to test your app. You actually have to request an access token to tickle the SOE.

The problem, if such it is, is in Spring OAuth because we already create a @Bean of type ClientDetailsService in the framework. By some weird accident, your @Bean method has the same name as that one and overrides it in the sunny day. When you create a @Service and component scan it, the bean name is different so the override is not possible. The override is essentially random though, unless you can control the order of bean registration, so you shouldn't rely on it. A nice way to fix it would be to use a @Conditional to back off from the @Bean in the framework (but we can't do that because we compile against an older version of Spring).

The best workaround is to not create a bean of that type. Another is to not use @EnableAuthorizationServer. Not creating a bean at all is not that terrible. You generally only need it in one place, so a local method without the @Bean annotation will work fine for most purposes. Another workaround would be to use a BFPP to remove the framework-provided bean before anything gets instantiated.