spring生命周期-BeanPostProcessor使用与原理浅析

说明：BeanPostProcessor接口：bean的后置处理器；在bean初始化前后进行一些处理工作；postProcessBeforeInitialization:在初始化之前工作；postProcessAfterInitialization:在初始化之后工作

源码接口：

package org.springframework.beans.factory.config;

import org.springframework.beans.BeansException;

/**
 
 */
public interface BeanPostProcessor {

	/**
      初始化方法init-method,afterPropertiesSet 等方法执行之前执行
	 */
	Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException;

	/**
	 初始化方法init-method,afterPropertiesSet 等方法执行之后执行
	 */
	Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException;
}

实例：

@Component
public class MyBeanPostProcessor implements BeanPostProcessor {

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

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

public class Car {
    public Car(){
        System.out.println("car constructor...");
    }

    public void init(){
        System.out.println("car ... init...");
    }

    public void detory(){
        System.out.println("car ... detory...");
    }

}

@Configuration
@ComponentScan("top.daocaor.bean")
public class MainConfigOfLifeCycle {

    @Bean(initMethod = "init",destroyMethod = "detory")
    public Car car(){
        return new Car();
    }
}

public class IOCTest_LifeCycle {

    @Test
    public void test1(){

        AnnotationConfigApplicationContext applicationContext = new AnnotationConfigApplicationContext(MainConfigOfLifeCycle.class);

        System.out.println("容器创建完成");

        //applicationContext.getBean("car");

        applicationContext.close();
    }
}

结果

源码分析：
可以在这里打断点，查看调用栈