Bean生命周期

package xyz.pascall.spring.learn.component;

import lombok.ToString;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;import org.springframework.beans.factory.config.BeanPostProcessor;
import org.springframework.core.Ordered;
import org.springframework.stereotype.Component;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;

/**
 * SpringBeanPostProcessorLive
 * <p>
 * 一：实例化
 *      BeanFactory: 第一次请求时，初始化bean通过调用createBean实例化
 *      ApplicationContext: 容器启动结束后，通过BeanDefinition实例化所用bean
 * 二：设置对象属性（依赖注入）
 *      （bean被封装到BeanWrapper中）Spring根据BeanDefinition和BeanWrapper提供的属性设置接口完成依赖注入
 * 三：处理Aware接口
 *      1.ApplicationContextAware(*)
 *      2.ApplicationEventPublisherAware
 *      3.BeanClassLoaderAware(*)
 *      4.BeanFactoryAware
 *      5.BeanNameAware
 *      6.EmbeddedValueResolverAware
 *      7.EnvironmentAware(*)
 *      8.ImportAware
 *      9.LoadTimeWeaverAware
 *      10.MessageSourceAware
 *      11.NotificationPublisherAware
 *      12.ResourceLoaderAware
 *      13.ServletConfigAware
 *      14.ServletContextAware
 * 四：init-method（@init-method）
 * 五：InitializingBean（bean属性设置之后接口）
 * 六：BeanPostProcessor.postProcessBeforeInitialization(Object, String)
 * 七：BeanPostProcessor.postProcessAfterInitialization(Object, String)
 * =====================================================================
 * 八：DisposableBean
 * 九：destroy-method
 *
 *
 * =====================================================================
 * =====================================================================
 * 1.工厂后置处理器(容器级)
 *      BeanFactoryPostProcessor
 *          AspectJWeavingEnabler
 *          ConfigurationClassPostProcessor
 *          CustomAutowireConfigurer
 * 2.容器级别生命周期处理器(实现类“后处理器”)
 *      InstantiationAwareBeanPostProcessor
 *      BeanPostProcessor
 * 3.Bean级生命周期接口方法
 *      BeanNameAware
 *      BeanFactoryAware
 *      InitializingBean
 *      DiposableBean
 * 4.Bean自身的方法
 *      init-method
 *      destroy-method
 *
 * *********************************************************************
 * *********************************************************************
 * BeanFactoryPostProcessor加载顺序：
 *      1.PriorityOrdered
 *      2.Ordered
 *      3.无排序
 *
 *    Spring解析处理所有@Configuration标签类，并将Bean定义注册到BeanFactory中
 *      1.internalConfigurationAnnotationProcessor  -> ConfigurationClassPostProcessor      -> PriorityOrdered
 *
 *    Spring通过EventListenerMethodProcessor来处理@EventListener注解
 *    ** 自定义listener使用@EventListener注解在监听的方法上
 *    ** Spring通过EventListenerMethodProcessor解析配置类包含@EventListener的方法
 *    ** 通过DefaultEventListenerFactory将其转化为ApplicationListenerMethodAdapter#ApplicationListenerMethodAdapter对象
 *      1.internalEventListenerProcessor            -> EventListenerMethodProcessor
 * *********************************************************************
 * *********************************************************************
 * BeanPostProcessor加载顺序：
 *      1、找到所有实现PriorityOrdered的BeanPostProcessor，然后getBean，然后统一排序，然后beanFactory.addBeanPostProcessor(..)
 *        2、找到所有实现Ordered的BeanPostProcessor，然后getBean，然后统一排序，然后beanFactory.addBeanPostProcessor(..)
 *        3、找到所有没实现排序接口的BeanPostProcessor，不需要sort，直接beanFactory.addBeanPostProcessor(..)
 *      4、最后注册一个特殊的处理器，beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(applicationContext));
 *
 *    Spring定义的没有排序的BeanPostProcessor
 *      1.ApplicationContextAwareProcessor(*)   -> 比较特殊，处理感知接口Aware的BeanPostProcessor，被提前实例化
 *      2.ApplicationListenerDetector           -> 检查作用在Bean上的BeanPostProcessor的数量是否足够，否则PostProcessorRegistrationDelegate$BeanPostProcessorChecker
 *      3.ServletContextAwareProcessor
 *      4.ConfigurationClassPostProcessor$ImportAwareBeanPostProcessor
 *
 *    Spring中与注解@Autowired/@Resource有关的BeanPostProcessor最先被加载
 *      1.internalAutowiredAnnotationProcessor  -> AutowiredAnnotationBeanPostProcessor     -> PriorityOrdered
 *      2.internalCommonAnnotationProcessor     -> CommonAnnotationBeanPostProcessor        -> PriorityOrdered
 * *********************************************************************
 * *********************************************************************
 * InstantiationAwareBeanPostProcessor
 * *********************************************************************
 * *********************************************************************
 *
 * @author Jie Zhang, 2019/7/30
 * @version DEMO v1.0
 */
@Component
@Slf4j
@ToString
public class SpringBeanPostProcessorLive implements BeanNameAware, BeanPostProcessor, InitializingBean, DisposableBean, Ordered {

    private ComponentDemo componentDemo;

    /**
     * 1.初始化
     */public SpringBeanPostProcessorLive() {
        log.info("1.SpringBeanPostProcessorLive.SpringBeanPostProcessorLive()");
    }

    /**
     * 3.处理Aware接口（BeanNameAware）
     *
     * @param name
     */
    @Override
    public void setBeanName(String name) {
        log.info("3.BeanNameAware.setBeanName(String name)");
    }

    /**
     * 4.init-method
     */
    @PostConstruct
    public void init() {
        log.info("4.init-method");
    }

    /**
     * 5.InitializingBean
     *
     * @throws Exception
     */
    @Override
    public void afterPropertiesSet() throws Exception {
        log.info("5.InitializingBean.afterPropertiesSet()");
    }

    /**
     * 6.处理bean后置处理器前置方法
     *
     * @param bean
     * @param beanName
     * @return
     * @throws BeansException
     */
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        log.info("6.BeanPostProcessor.postProcessBeforeInitialization(Object bean, String beanName)");
        log.info(beanName);
        if (bean instanceof ComponentDemo) {
            this.componentDemo = (ComponentDemo)bean;
        }
        return bean;
    }

    /**
     * 7.处理bean后置处理器后置方法
     *
     * @param bean
     * @param beanName
     * @return
     * @throws BeansException
     */
    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        log.info("7.BeanPostProcessor.postProcessAfterInitialization(Object bean, String beanName)");
        log.info(beanName);
        return bean;
    }


    /////////////////////////////////////////////////////////////////////////////////////////////////

    /**
     * 8.DisposableBean
     * @throws Exception
     */
    @Override
    public void destroy() throws Exception {
        log.info("8.DisposableBean.destroy()");
    }

    /**
     * 9.destroy-method
     */
    @PreDestroy
    public void destroyMethod() {
        log.info("9.destroy-method");
    }

    @Override
    public int getOrder() {
        return Integer.MAX_VALUE;
    }
}

 参考文章：

【小家Spring】Spring IOC容器启动流程 AbstractApplicationContext#refresh()方法源码分析（一）