Spring AOT no longer generates BeanInstanceSupplier signature for a CGLIB proxy with its public type

After upgrading to Sprint Boot 3.4.0, I got this error:

> Task :compileAotTestJava FAILED
C:\Users\fouad\IdeaProjects\spring-boot-3.4-bug\build\generated\aotTestSources\io\fouad\SecurityConfig__TestContext001_BeanDefinitions.java:34: error: incompatible types: BeanInstanceSupplier<SecurityConfig$$SpringCGLIB$$0> cannot be converted to InstanceSupplier<SecurityConfig>
    InstanceSupplier<SecurityConfig> instanceSupplier = getSecurityConfigInstanceSupplier();
                                                                                         ^

Here is a reproducer: https://github.com/Eng-Fouad/spring-boot-3.4-bug

Comment From: snicoll

@Eng-Fouad thanks for the sample, I can reproduce the problem.

I suppose the actual code is more involved but mixing autowiring like that is a bit strange, especially if you target native images as you may want your config arrangement to be as lean as possible. Rather than mixing things, you could rewrite the constructor as follows:

public SecurityConfig(OAuth2AuthEntryPoint oAuth2AuthEntryPoint, @Value("${app.jwt.signature.public-key}") jwtSignaturePublicKeyBase64) {
    this.oAuth2AuthEntryPoint = oAuth2AuthEntryPoint;
    this.jwtSignaturePublicKeyBase64 = jwtSignaturePublicKeyBase64;
}

And make jwtSignaturePublicKeyBase64 final. Once you've done that, you can switch @Configuration to use proxyBeanMethods = false and it won't have to create a CGLIB proxy for it.

Comment From: Eng-Fouad

@Eng-Fouad thanks for the sample, I can reproduce the problem.

I suppose the actual code is more involved but mixing autowiring like that is a bit strange, especially if you target native images as you may want your config arrangement to be as lean as possible. Rather than mixing things, you could rewrite the constructor as follows:

java public SecurityConfig(OAuth2AuthEntryPoint oAuth2AuthEntryPoint, @Value("${app.jwt.signature.public-key}") jwtSignaturePublicKeyBase64) { this.oAuth2AuthEntryPoint = oAuth2AuthEntryPoint; this.jwtSignaturePublicKeyBase64 = jwtSignaturePublicKeyBase64; }

And make jwtSignaturePublicKeyBase64 final. Once you've done that, you can switch @Configuration to use proxyBeanMethods = false and it won't have to create a CGLIB proxy for it.

Thanks for the tips.

Comment From: snicoll

This regression has a larger scope but you're affected specifically due to the mixed nature of autowiring.