Spring Boot Web (Gradle config) breaks when I add AOP/Advice - spring

Question

I'm faily sure this is a missconfiguration, I just don't know which part since the AOP tutorials i found all used Maven, but I use Gradle.
So I took the project that start.spring.io creates (Kotlin 1.5.21, Gradle 7.1.1, Spring Boot 2.5.3) with a starter for spring-boot-starter-web.
plugins {
id("org.springframework.boot") version "2.5.3"
id("io.spring.dependency-management") version "1.0.11.RELEASE"
kotlin("jvm") version "1.5.21"
kotlin("plugin.spring") version "1.5.21"
}
dependencies {
implementation("org.springframework.boot:spring-boot-starter-web")
implementation("com.fasterxml.jackson.module:jackson-module-kotlin")
implementation("org.jetbrains.kotlin:kotlin-reflect")
}
Then I added
implementation("org.springframework.boot:spring-boot-starter-aop")
and an Advice
#Target(AnnotationTarget.FUNCTION) #MustBeDocumented
annotation class UserAuthorized(val roles: Array<String>)
#Component #Aspect
class UserAuthorizedAdvice {
#Pointcut("#target(com.example.springbootplayground2.auth.UserAuthorized)")
fun userAuthorizedMethods() {}
#Before("userAuthorizedMethods()")
fun checkIfUserHasRequiredRole(jp: JoinPoint) {...}
}
Now the app crashes at startup (error messages at the end). I tried to fix it with adding the #EnableAspectJAutoProxy annotation, but it didn't help.
#SpringBootApplication
#EnableAspectJAutoProxy(proxyTargetClass=true)
class SpringbootPlayground2Application
On Linux this crashes with
org.springframework.context.ApplicationContextException: Unable to start web server; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'tomcatServletWebServerFactory' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/ServletWebServerFactoryConfiguration$EmbeddedTomcat.class]: Initialization of bean failed; nested exception is org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'errorPageCustomizer' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/error/ErrorMvcAutoConfiguration.class]: Unsatisfied dependency expressed through method 'errorPageCustomizer' parameter 0; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dispatcherServletRegistration' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/DispatcherServletAutoConfiguration$DispatcherServletRegistrationConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.boot.autoconfigure.web.servlet.DispatcherServletRegistrationBean]: Factory method 'dispatcherServletRegistration' threw exception; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'multipartConfigElement' defined in class path resource [org/springframework/boot/autoconfigure/web/servlet/MultipartAutoConfiguration.class]: Initialization of bean failed; nested exception is org.springframework.aop.framework.AopConfigException: Unexpected AOP exception; nested exception is java.lang.NullPointerException: Cannot invoke "Object.getClass()" because "cause" is null
caused by
Caused by: java.lang.NullPointerException: Cannot invoke "Object.getClass()" because "cause" is null
at org.springframework.cglib.core.CodeGenerationException.<init>(CodeGenerationException.java:25) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:587) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:363) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:585) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:110) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:108) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54) ~[spring-core-5.3.9.jar:5.3.9]
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) ~[na:na]
at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:134) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:319) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:572) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:419) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.ObjenesisCglibAopProxy.createProxyClassAndInstance(ObjenesisCglibAopProxy.java:57) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.CglibAopProxy.getProxy(CglibAopProxy.java:206) ~[spring-aop-5.3.9.jar:5.3.9]
On MacOs (M1-cpu) this crashes with java.lang.NullPointerException: null caused by
Caused by: org.springframework.boot.web.server.WebServerException: Unable to start embedded Tomcat
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:142) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.<init>(TomcatWebServer.java:104) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getTomcatWebServer(TomcatServletWebServerFactory.java:450) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory.getWebServer(TomcatServletWebServerFactory.java:199) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory$$FastClassBySpringCGLIB$$9c83fa9f.invoke(<generated>) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:218) ~[spring-core-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:779) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:750) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:180) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:750) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:97) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:750) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:692) ~[spring-aop-5.3.9.jar:5.3.9]
at org.springframework.boot.web.embedded.tomcat.TomcatServletWebServerFactory$$EnhancerBySpringCGLIB$$f87b4803.getWebServer(<generated>) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.createWebServer(ServletWebServerApplicationContext.java:182) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.onRefresh(ServletWebServerApplicationContext.java:160) ~[spring-boot-2.5.3.jar:2.5.3]
... 8 common frames omitted
Caused by: java.lang.IllegalStateException: StandardEngine[Tomcat].StandardHost[localhost].TomcatEmbeddedContext[] failed to start
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.rethrowDeferredStartupExceptions(TomcatWebServer.java:187) ~[spring-boot-2.5.3.jar:2.5.3]
at org.springframework.boot.web.embedded.tomcat.TomcatWebServer.initialize(TomcatWebServer.java:126) ~[spring-boot-2.5.3.jar:2.5.3]
... 25 common frames omitted
Update
here you can find a minimal version of my project
Update2
the project now has a solution branch incorporating kriegaex' fix.

Answer 1

Actually, I was so focused on helping you fix your scoping problem and then thinking about your description of the aspect not being picked up, that I overlooked the obvious:
You are simply using the wrong pointcut type. #target() is for type annotations, while you use a method annotation requiring an #annotation() pointcut:
#Pointcut("#annotation(com.example.springbootplayground2.UserAuthorized)")
fun userAuthorizedMethods() {}
Now your aspect kicks in, and because #annotation() can be determined statically, you do not even need && within(...). But it is always a good idea to add it as a safeguard.
Lesson learned for you: Always try presenting all relevant code, always post an MCVE if you are not sure where the error is located. You did not post your controller with the annotated method, otherwise I might have noticed right away. Now I only had a chance to notice the glitch after cloning your repository and waiting for Gradle to do its bandwidth-eating download thing. 😏