Spring源码分析-IOC之BeanPostProcessor

BeanPostProcessor:主要用于我们想在spring容器完成bean实例化,配置以及其他初始化方法前后要添加自己的逻辑处理,则我们需要用到BeanPostProcessor的接口实现类,然后注册到ioc容器中:

package com.ck.ioc;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;

public class TestBeanPostProcessor implements BeanPostProcessor{

	@Override
	public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
		System.out.println("postProcessBeforeInitialization");
		return bean;
	}

	@Override
	public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
		System.out.println("postProcessAfterInitialization");
		return bean;
	}

}

注意:接口中两个方法不能返回null，如果返回null那么在后续初始化方法将报空指针异常或者通过getBean()方法获取不到bean实例对象因为后置处理器从Spring IoC容器中取出bean实例对象没有再次放回IoC容器中

package com.ck.bean;


import java.io.Serializable;

public class Person implements Serializable{
	
	private static final long serialVersionUID = 1L;

	private Long id;
	
	private String name;
	
	private String sex;
	
	private Integer age;
	
	
	public Person() {
		System.out.println("constructor");
	}

	public Long getId() {
		return id;
	}

	public void setId(Long id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}


	public String getSex() {
		return sex;
	}


	public void setSex(String sex) {
		this.sex = sex;
	}

	public Integer getAge() {
		return age;
	}

	public void setAge(Integer age) {
		this.age = age;
	}
	
}

配置文件如下:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns:aop="http://www.springframework.org/schema/aop"
	xmlns:context="http://www.springframework.org/schema/context"
	xmlns:mvc="http://www.springframework.org/schema/mvc"
	xmlns:tx="http://www.springframework.org/schema/tx"
	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.1.xsd
		http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.1.xsd
		http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.1.xsd
		http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.1.xsd
		http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.1.xsd">

	<bean id="person" class="com.ck.bean.Person"></bean>
	<bean class="com.ck.ioc.TestBeanPostProcessor"/>
</beans>

测试结果如下:

三月 19, 2019 4:47:06 下午 org.springframework.context.support.FileSystemXmlApplicationContext prepareRefresh
信息: Refreshing org.springframework.context.support.FileSystemXmlApplicationContext@16b4a017: startup date [Tue Mar 19 16:47:06 CST 2019]; root of context hierarchy
三月 19, 2019 4:47:06 下午 org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
信息: Loading XML bean definitions from file [X:\CK\stsws\springWeb\src\main\resources\applicationContext.xml]
constructor
postProcessBeforeInitialization
postProcessAfterInitialization

Spring源码分析-IOC之BeanPostProcessor

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