spring aop @target and @within throw IllegalAccessError

Question

when run the application, it throws IllegalAccessError，Application run failed

here is demo aop、service、annotation used，a simple annotation and @Before advice，also enable @EnableAspectJAutoProxy

@Target({ElementType.TYPE, ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface MethodInterceptAnnotation {
}

@Component
@Aspect
public class MethodInterceptAop {
    @Before("@target(com.example.demo.aop.MethodInterceptAnnotation)")
    public void beforeCheck() {
        System.out.println("before check");
    }
}

public interface UserService {
    String getUserName(int a);
}

@Service
public class UserServiceImpl implements UserService {
    @MethodInterceptAnnotation
    public String getUserName(int age) {
        System.out.println("age:" + age);
        return age + "";
    }
}

change@target to @within error again, but change@target to @annotation everything is ok

here is partial stacktrace

Caused by: org.springframework.cglib.core.CodeGenerationException: java.lang.IllegalAccessError-->class org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryConfiguration$EmbeddedTomcat$$EnhancerBySpringCGLIB$$e5c9e457 cannot access its superclass org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryConfiguration$EmbeddedTomcat
    at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:538) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.core.AbstractClassGenerator.generate(AbstractClassGenerator.java:363) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.proxy.Enhancer.generate(Enhancer.java:582) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:110) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData$3.apply(AbstractClassGenerator.java:108) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.core.internal.LoadingCache$2.call(LoadingCache.java:54) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at java.util.concurrent.FutureTask.run(FutureTask.java:266) ~[na:1.8.0_201]
    at org.springframework.cglib.core.internal.LoadingCache.createEntry(LoadingCache.java:61) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.core.internal.LoadingCache.get(LoadingCache.java:34) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.core.AbstractClassGenerator$ClassLoaderData.get(AbstractClassGenerator.java:134) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.core.AbstractClassGenerator.create(AbstractClassGenerator.java:319) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.proxy.Enhancer.createHelper(Enhancer.java:569) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.cglib.proxy.Enhancer.createClass(Enhancer.java:416) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.aop.framework.ObjenesisCglibAopProxy.createProxyClassAndInstance(ObjenesisCglibAopProxy.java:57) ~[spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy.getProxy(CglibAopProxy.java:205) ~[spring-aop-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    ... 37 common frames omitted
Caused by: java.lang.IllegalAccessError: class org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryConfiguration$EmbeddedTomcat$$EnhancerBySpringCGLIB$$e5c9e457 cannot access its superclass org.springframework.boot.autoconfigure.web.servlet.ServletWebServerFactoryConfiguration$EmbeddedTomcat
    at java.lang.ClassLoader.defineClass1(Native Method) ~[na:1.8.0_201]
    at java.lang.ClassLoader.defineClass(ClassLoader.java:763) ~[na:1.8.0_201]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_201]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_201]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_201]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_201]
    at org.springframework.cglib.core.ReflectUtils.defineClass(ReflectUtils.java:535) ~[spring-core-5.2.4.RELEASE.jar:5.2.4.RELEASE]
    ... 51 common frames omitted

anyone know what is wrong with this code, thanks in advance.

Answer 1

From the documentation : Supported Pointcut Designators

@target: Limits matching to join points (the execution of methods when using Spring AOP) where the class of the executing object has an annotation of the given type.

@within: Limits matching to join points within types that have the given annotation (the execution of methods declared in types with the given annotation when using Spring AOP).

Both @target and @within advice types are for the class/type .

The scope of the pointcut is global and when the application starts up it tries to identify all the classes/types with annotation and interferes with unwanted classes , here EmbeddedTomcat related.

For @target and @within advice types to work , try narrowing the scope by adding a scoping designator as follows

@Before("@target(com.example.demo.aop.MethodInterceptAnnotation) && within(com.example.demo..*)")

For me , narrowing the scope have always worked , but have come across SO questions where that too did not help. In that case , resolution for your issue is available in this answer from @kriegaex.

Please go through the answer and comments to understand the difference when @annotation is used. To summarize , advice types @target and @within when used , tends to create proxies for all classes irrespective if the annotation is present or not at class level.

Hope this helps.