Spring 前置和后置处理器

今天处理一个问题，需要扫描java方法上面自定义注解。代码使用的spring后置处理器BeanPostProcessor.java的postProcessAfterInitialization()，方法代码如下

    @Override
    @Retryable(value = Exception.class, maxAttempts = 5, backoff = @Backoff(delay = 3000, multiplier = 2, maxDelay = 20000))
    @CustomAnnotation
    public void testRetry() {
        System.out.println("in test retry: " + System.currentTimeMillis() / 1000);
        int a = 1 / 0;
        System.out.println("end in test retry");
    }

有两个注解一个自定义、一个spring重试的注解。

后置处理器代码：

@Component
public class CustomBeanProcessor implements BeanPostProcessor {
    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        Method[] methods = bean.getClass().getDeclaredMethods();
        for (Method method : methods) {
            CustomAnnotation customAnnotation = method.getAnnotation(CustomAnnotation.class);
            if (beanName.equals("retryServiceImpl"))
                System.out.println("beanName:" + beanName + ", method name: " + method.getName() + ", customAnnotation: " + customAnnotation);
            if (customAnnotation != null) {
                System.out.println("##############");
            }
        }
        return bean;
    }
}

预期希望进入11行，输出#####。实际没有输出，通过9行打印bean和对应的方法

 有cglib关键字和一些spring生成的方法。可以判断spring通过cglib生成了其他方法，也影响到了注解的扫描。

修改为使用前置处理器，这个时候bean还没有被初始化，应该还没有被cglib处理。修改为前置处理器

@Component
public class CustomBeanProcessor implements BeanPostProcessor {
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        Method[] methods = bean.getClass().getDeclaredMethods();
        for (Method method : methods) {
            CustomAnnotation customAnnotation = method.getAnnotation(CustomAnnotation.class);
            if (beanName.equals("retryServiceImpl"))
                System.out.println("beanName:" + beanName + ", method name: " + method.getName() + ", customAnnotation: " + customAnnotation);
            if (customAnnotation != null) {
                System.out.println("##############");
            }
        }
        return bean;
    }
}

扫描到自定义注解，打印出####