1. BeanPostProcessor簡(jiǎn)介
BeanPostProcessor是Spring IOC容器給我們提供的一個(gè)擴(kuò)展接口充蓝。接口聲明如下：
public interface BeanPostProcessor {
//bean初始化方法調(diào)用前被調(diào)用
Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException;
//bean初始化方法調(diào)用后被調(diào)用
Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException;
}
運(yùn)行順序
===Spring IOC容器實(shí)例化Bean===
===調(diào)用BeanPostProcessor的postProcessBeforeInitialization方法===
===調(diào)用bean實(shí)例的初始化方法===
===調(diào)用BeanPostProcessor的postProcessAfterInitialization方法===
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2. BeanPostProcessor實(shí)例
/**
* 后置處理器：初始化前后進(jìn)行處理工作
* 將后置處理器加入到容器中
*/
@Component
public class MyBeanPostProcessor implements BeanPostProcessor {
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
// TODO Auto-generated method stub
System.out.println("postProcessBeforeInitialization..."+beanName+"=>"+bean);
return bean;
}
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
// TODO Auto-generated method stub
System.out.println("postProcessAfterInitialization..."+beanName+"=>"+bean);
return bean;
}
}
3. BeanFactoryPostProcessor簡(jiǎn)介
bean工廠的bean屬性處理容器，說通俗一些就是可以管理我們的bean工廠內(nèi)所有的beandefinition（未實(shí)例化）數(shù)據(jù)，可以隨心所欲的修改屬性。
4. BeanFactoryPostProcessor實(shí)例
@Component
public class MyBeanFactoryPostProcessor implements BeanFactoryPostProcessor {
@Override
public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
System.out.println("MyBeanFactoryPostProcessor...postProcessBeanFactory...");
int count = beanFactory.getBeanDefinitionCount();
String[] names = beanFactory.getBeanDefinitionNames();
System.out.println("當(dāng)前BeanFactory中有"+count+" 個(gè)Bean");
System.out.println(Arrays.asList(names));
}
}
區(qū)別：
注冊(cè)BeanFactoryPostProcessor的實(shí)例够颠，需要重載
void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException;
通過beanFactory可以獲取bean的示例或定義等茎匠。同時(shí)可以修改bean的屬性，這是和BeanPostProcessor最大的區(qū)別吱晒。
