spring 加载bean的一些操作

BeanFactoryPostProcessor

/**
 * BeanFactoryPostProcessor 优先级高，只执行一次，可以使用迭代器遍历所有已加载的bean
 * 然后再对bean进行操作
 * 在该阶段 bean还没有进行初始化
 *
 */
@Component
public class BeanFactoryPostProcessorTest implements BeanFactoryPostProcessor {

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory configurableListableBeanFactory) throws BeansException {
         Iterator<String> beanNamesIterator = configurableListableBeanFactory.getBeanNamesIterator();
         while (beanNamesIterator.hasNext()) {
             String beanName = beanNamesIterator.next();
             System.out.println(beanName);
         }
    }
}

BeanPostProcessor

/**
 *
 * bean 加载时的监听处理
 *BeanPostProcessor 和 BeanFactoryPostProcessor 的可见区别
 * BeanPostProcessor是遍历每个bean，而 BeanFactoryPostProcessor时只执行一次并且优先于BeanPostProcessor
 */
@Component
public class BeanPostProcessorTest implements BeanPostProcessor {

    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        return BeanPostProcessor.super.postProcessBeforeInitialization(bean, beanName);
    }

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        // bean加载后，可以对已经加载到容器里的bena进行操作
        if(beanName.equals("student")){
            Student beans = (Student) bean;
            beans.setName("1111");
            return bean;
        }
        return BeanPostProcessor.super.postProcessAfterInitialization(bean, beanName);
    }
}