Spring之BeanFactoryPostProcessor接口介绍

public interface BeanFactoryPostProcessor {

	/**
	 * Modify the application context's internal bean factory after its standard
	 * initialization. All bean definitions will have been loaded, but no beans
	 * will have been instantiated yet. This allows for overriding or adding
	 * properties even to eager-initializing beans.
	 * @param beanFactory the bean factory used by the application context
	 * @throws org.springframework.beans.BeansException in case of errors
	 */
	void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException;

}

/**
 * 自定义BeanFactoryPostProcessor
 * 
 * @author dengp
 *
 */
public class MyBeanFactoryPostProcessor implements BeanFactoryPostProcessor {

	/**
	 * 本方法在Bean对象实例化之前执行，
	 * 通过beanFactory可以获取bean的定义信息，
	 * 并可以修改bean的定义信息。这点是和BeanPostProcessor最大区别
	 */
	@Override
	public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
		
		System.out.println(">> BeanFactoryPostProcessor 开始执行了");
		String[] names = beanFactory.getBeanDefinitionNames();
		for (String name : names) {
			if("user".equals(name)){
				
				BeanDefinition beanDefinition = beanFactory.getBeanDefinition(name);
				MutablePropertyValues propertyValues = beanDefinition.getPropertyValues();
				// MutablePropertyValues如果设置了相关属性，可以修改，如果没有设置则可以添加相关属性信息
				if(propertyValues.contains("name")){
					propertyValues.addPropertyValue("name", "bobo");
					System.out.println("修改了属性信息");
				}
			}
		}
		System.out.println(">> BeanFactoryPostProcessor 执行结束");
	}
}

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://www.springframework.org/schema/beans 
 http://www.springframework.org/schema/beans/spring-beans.xsd">

	<bean class="com.dpb.pojo.User" id="user" init-method="start">
		<property name="name" value="波波烤鸭"></property>
	</bean>
	
	<!-- 注册处理器 -->
	<bean class="com.dpb.processor.MyBeanPostProcessor"/>
	<!-- 注册BeanFactoryPostProcessor -->
	<bean class="com.dpb.factoryprocessor.MyBeanFactoryPostProcessor"></bean>
</beans>

@Test
public void test1() {
	ApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
	User user = ac.getBean(User.class);
	System.out.println(user);
}

>> BeanFactoryPostProcessor 开始执行了
修改了属性信息
>> BeanFactoryPostProcessor 执行结束
User 被实例化
设置：bobo
A before--实例化的bean对象:User [id=0, name=bobo, beanName=null]	user
User 中自定义的初始化方法
A after...实例化的bean对象:User [id=0, name=bobo, beanName=null]	user
User [id=0, name=bobo, beanName=null]