spring aop @target和@within抛出IllegalAccessError

Question

[运行应用程序时，它抛出IllegalAccessError，应用程序运行失败

这里是演示aop，service，annotation，使用了简单的注释和@Before建议，还启用了@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 + "";
    }
}

@target更改为@within错误，但将@target更改为@annotation一切正常

这里是部分堆栈跟踪

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

任何人都知道这段代码出了什么问题，谢谢。

Answer 1

从文档中：Supported Pointcut Designators

@ target：限制匹配连接点（在以下情况下执行方法：使用Spring AOP），其中执行对象的类具有给定类型的注释。

@@ inin：将匹配限制为在具有给定注释（以类型声明的方法的执行使用Spring AOP时给定注释）。

@target和@within通知类型均适用于class / type。

切入点的范围是全局的，并且在应用程序启动时，它尝试标识所有带有注释的类/类型，并干扰不需要的类，在此与EmbeddedTomcat相关。

为了使@target和@within通知类型起作用，请尝试通过添加作用域指示符来缩小范围，如下所示

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

对我来说，缩小范围始终是可行的，但是遇到了SO questions，但这也无济于事。在这种情况下，可以通过@kriegaex在此answer中找到解决问题的方法。

请仔细阅读答案和注释以了解使用@annotation时的区别。总而言之，建议类型@target和@within在使用时，往往会为所有类创建代理，无论注释是否存在于类级别。

希望这会有所帮助。