Spring 前置和后置處理器

今天處理一個問題，需要掃描java方法上面自定義注解。代碼使用的spring后置處理器BeanPostProcessor.java的postProcessAfterInitialization()，方法代碼如下

    @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");
    }

有兩個注解一個自定義、一個spring重試的注解。

后置處理器代碼：

@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;
    }
}

預期希望進入11行，輸出#####。實際沒有輸出，通過9行打印bean和對應的方法

 

 有cglib關鍵字和一些spring生成的方法。可以判斷spring通過cglib生成了其他方法，也影響到了注解的掃描。

修改為使用前置處理器，這個時候bean還沒有被初始化，應該還沒有被cglib處理。修改為前置處理器

@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;
    }
}

掃描到自定義注解，打印出####