Spring AOP代理在BeanPostProcessor与FactoryBean依赖下失效问题

问题描述 #

当自定义BeanPostProcessor（MyPostProcessor）和FactoryBean（MyFactoryBean）结合使用时，Spring AOP无法为HelloService Bean生成代理，最终返回的是普通Java对象，无任何代理逻辑。
只有当BeanPostProcessor依赖另一个Bean（如本例中的GoodByeService）时，才会触发该问题。

预期行为 #

HelloService Bean应被AOP代理，以下检查需返回true：

• AopUtils.isAopProxy(helloService)
• AopUtils.isJdkDynamicProxy(helloService) 或 AopUtils.isCglibProxy(helloService)
  同时，调用HelloService的sayHello方法时，MyAspect中的@AfterReturning通知需被触发。

实际行为 #

HelloService Bean未被代理，以下检查均返回false：

• AopUtils.isAopProxy(helloService)
• AopUtils.isJdkDynamicProxy(helloService)
• AopUtils.isCglibProxy(helloService)
  且MyAspect中的@AfterReturning通知未被触发。

复现步骤 #

以下是最小可复现示例：

POM文件

<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <artifactId>spring-aop</artifactId>
    <parent>
        <groupId>com.cj.lb</groupId>
        <artifactId>spring-exploration</artifactId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <properties>
        <spring-versrion>6.0.11</spring-versrion>
        <java.version>17</java.version>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>${spring-versrion}</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>${spring-versrion}</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.5</version>
        </dependency>
    </dependencies>
</project>

配置类

@EnableAspectJAutoProxy
@Configuration
@ComponentScan
public class MyConfig {

    @Bean
    MyPostProcessor myPostProcessor(GoodByeService goodByeService) {
        MyPostProcessor myPostProcessor = new MyPostProcessor();
        myPostProcessor.setGoodByeService(goodByeService);
        return myPostProcessor;
    }
    
    @Bean
    MyFactoryBean myFactoryBean(HelloService helloService) {
        MyFactoryBean myFactoryBean = new MyFactoryBean();
        myFactoryBean.setHelloService(helloService);
        return myFactoryBean;
    }

}

BeanPostProcessor实现类

public class MyPostProcessor implements Ordered, BeanPostProcessor {

    private GoodByeService goodByeService;
    
    public GoodByeService getGoodByeService() {
        return goodByeService;
    }
    
    public void setGoodByeService(GoodByeService goodByeService) {
        this.goodByeService = goodByeService;
    }
    
    @Override
    public int getOrder() {
        return 0;
    }

}

服务类

@Service
public class HelloServiceImpl implements HelloService {

    @Override
    public String sayHello() {
        String result = "hello world";
        System.out.println(result);
        return result;
    }

}

@Service
public class GoodByeServiceImpl implements GoodByeService {
    @Override
    public String sayGoodbye() {
        return "Goodbye";
    }
}

FactoryBean实现类

public class MyFactoryBean implements FactoryBean {

    private HelloService helloService;
    
    public HelloService getHelloService() {
        return helloService;
    }
    
    public void setHelloService(HelloService helloService) {
        this.helloService = helloService;
    }
    
    @Override
    public Object getObject() throws Exception {
        return new MyBean();
    }
    
    @Override
    public Class<?> getObjectType() {
        return MyBean.class;
    }
    
    public static class MyBean {
    }

}

切面类

@Component
@Aspect
public class MyAspect {

    @Pointcut("execution(* com.cj.lb.service.HelloService.sayHello(..))")
    public void pointcut() {}
    
    @AfterReturning(pointcut = "pointcut()", returning = "result")
    public void afterReturning(JoinPoint jp, Object result) {
        System.out.println("my aspect aop ...");
    }

}

主类

public class Main {

    public static void main(String[] args) {
        AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(MyConfig.class);
    
        HelloService helloService = context.getBean(HelloService.class);
        System.out.println("helloService.getClass() = " + helloService.getClass());
    
        System.out.println("Is AOP Proxy: " + AopUtils.isAopProxy(helloService));
        System.out.println("Is JDK Dynamic Proxy: " + AopUtils.isJdkDynamicProxy(helloService));
        System.out.println("Is CGLIB Proxy: " + AopUtils.isCglibProxy(helloService));
    
        context.close();
    }

}

输出结果

helloService.getClass() = class com.cj.lb.service.impl.HelloServiceImpl
Is AOP Proxy: false
Is JDK Dynamic Proxy: false
Is CGLIB Proxy: false

分析与解决方案 #

该问题可通过以下任一方式解决：

1. 在MyFactoryBean的HelloService依赖上添加@Lazy注解
2. 为MyFactoryBean添加正确的泛型声明（修改为public class MyFactoryBean implements FactoryBean<MyBean>）

疑问 #

1. 为什么带有依赖的BeanPostProcessor会影响HelloService的AOP代理创建？
2. 这是Spring的Bug，还是遗漏了特定的配置要求？

补充说明 #

该问题似乎与Bean初始化顺序或代理创建时机有关，尤其是涉及BeanPostProcessor和FactoryBean依赖时，希望得到进一步的澄清。

内容的提问来源于stack exchange，提问作者java-lbb