前言
記得以前的時候，每次提起Spring中的bean相關(guān)的生命周期時，內(nèi)心都無比的恐懼，因為好像有很多，自己又理不清楚：什么beanFactory啊，aware接口啊，beanPostProcessor啊，afterPropertiesSet啊，initMethod啊等等。
今天終于理清這些關(guān)系了，并且又新增了對postConstruct和lifecycle的理解。
執(zhí)行順序
- 首先是 BeanFactoryPostProcessor，它是針對所有bean的definition的，只執(zhí)行一次
下面是針對每個bean的初始
- - 實現(xiàn)了一系列aware接口的，比如BeanNameAware，ApplicationContextAware，調(diào)用其set方法
- - 執(zhí)行BeanPostProcessor的postProcessBeforeInitialization方法
- - 帶有@PostConstruct注解的方法
- - 實現(xiàn)InitializingBean接口的afterPropertiesSet方法
- - 指定的initMethod方法
- - 執(zhí)行BeanPostProcessor的postProcessAfterInitialization方法
- - 實現(xiàn)了SmartLifecycle接口的start方法(實現(xiàn)Lifecycle接口的不會自動調(diào)用，需要顯式的調(diào)用start方法)
下面是針對每個bean的銷毀
- - 實現(xiàn)了SmartLifecycle接口的stop方法(實現(xiàn)Lifecycle接口的不會自動調(diào)用，需要顯式的調(diào)用stop方法)
- - 帶有@PreDestroy注解的方法
- - 實現(xiàn)DisposableBean接口的destroy方法
- - 指定的destroyMethod方法
目前就想到這么多了，其他的麻煩在評論區(qū)留言呀~
代碼實例
bean實體類
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/** * @date: 2020-07-22 * * 一個簡單的枚舉類 */public enum BeanType { NORMAL, LIFECYCLE, SMART_LIFECYCLE;}import javax.annotation.PostConstruct;import javax.annotation.PreDestroy;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.context.ApplicationContext;import org.springframework.context.ApplicationContextAware;/** * @author: lihui * @date: 2020-07-22 * 一個簡單的bean */@Slf4jpublic class NormalBean implements BeanNameAware, ApplicationContextAware, InitializingBean, DisposableBean { private BeanType beanType; public NormalBean() { this(BeanType.NORMAL); } public NormalBean(BeanType beanType) { this.beanType = beanType; } @PostConstruct public void postConstruct() { log.info("{}, postConstruct", beanType); } @Override public void afterPropertiesSet() throws Exception { log.info("{}, afterPropertiesSet", beanType); } public void initMethod() { log.info("{}, initMethod", beanType); } @PreDestroy public void preDestroy() { log.info("{}, preDestroy", beanType); } @Override public void destroy() throws Exception { log.info("{}, destroy", beanType); } public void destroyMethod() { log.info("{}, destroyMethod", beanType); } @Override public void setApplicationContext(ApplicationContext applicationContext) throws BeansException { log.info("setApplicationContext, applicationContext : {}", applicationContext); } @Override public void setBeanName(String name) { log.info("setBeanName, bean name : {}", name); }}import lombok.extern.slf4j.Slf4j;import org.springframework.context.Lifecycle;/** * @author: lihui * @date: 2020-07-22 * 實現(xiàn)了Lifecycle的一個bean */@Slf4jpublic class LifecycleBean extends NormalBean implements Lifecycle { private volatile boolean running = false; public LifecycleBean() { super(BeanType.LIFECYCLE); } @Override public void start() { log.info("start"); running = true; } @Override public void stop() { log.info("stop"); running = false; } @Override public boolean isRunning() { return running; }}import lombok.extern.slf4j.Slf4j;import org.springframework.context.SmartLifecycle;/** * @author: lihui * @date: 2020-07-22 * 實現(xiàn)了SmartLifecycle的一個bean */@Slf4jpublic class SmartLifecycleBean extends NormalBean implements SmartLifecycle { private volatile boolean running = false; public SmartLifecycleBean() { super(BeanType.SMART_LIFECYCLE); } @Override public void start() { log.info("start"); running = true; } @Override public void stop() { log.info("stop"); running = false; } @Override public boolean isRunning() { return running; }} |
配置類
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import lombok.extern.slf4j.Slf4j;import org.springframework.beans.BeansException;import org.springframework.beans.factory.config.BeanFactoryPostProcessor;import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;/** * @author: lihui * @date: 2020-07-25 */@Slf4jpublic class MyBeanFactoryPostProcessor implements BeanFactoryPostProcessor { @Override public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException { log.info("postProcessBeanFactory, beanFactory:{}", beanFactory); }}import lombok.extern.slf4j.Slf4j;import org.springframework.beans.BeansException;import org.springframework.beans.factory.config.BeanPostProcessor;/** * @author: lihui * @date: 2020-07-25 */@Slf4jpublic class MyBeanPostProcessor implements BeanPostProcessor { @Override public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException { log.info("postProcessBeforeInitialization, bean:{}", beanName); return bean; } @Override public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException { log.info("postProcessAfterInitialization, bean:{}", beanName); return bean; }}import lombok.extern.slf4j.Slf4j;import org.springframework.context.SmartLifecycle;import org.springframework.context.annotation.Bean;import org.springframework.context.annotation.Configuration;/** * @author: lihui * @date: 2020-07-22 */@Configuration@Slf4jpublic class Config { @Bean(initMethod = "initMethod", destroyMethod = "destroyMethod") public NormalBean normalBean() { return new NormalBean(); } @Bean(initMethod = "initMethod", destroyMethod = "destroyMethod") public LifecycleBean lifecycleBean() { return new LifecycleBean(); } @Bean(initMethod = "initMethod", destroyMethod = "destroyMethod") public SmartLifecycle smartLifecycle() { return new SmartLifecycleBean(); } @Bean public static MyBeanFactoryPostProcessor myBeanFactoryPostProcessor() { return new MyBeanFactoryPostProcessor(); } @Bean public static MyBeanPostProcessor myBeanPostProcessor() { return new MyBeanPostProcessor(); }} |
Main類
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import lombok.extern.slf4j.Slf4j;import org.springframework.context.ConfigurableApplicationContext;import org.springframework.context.annotation.AnnotationConfigApplicationContext;/** * @author: lihui * @date: 2020-07-22 */@Slf4jpublic class Main { public static void main(String[] args) throws InterruptedException { ConfigurableApplicationContext ctx = new AnnotationConfigApplicationContext(Config.class); ctx.registerShutdownHook(); Thread.sleep(5000); log.info("line ----------------------------- line"); ctx.start(); ctx.stop(); log.info("line ----------------------------- line"); }} |
結(jié)果說明
結(jié)果正如前面所說的執(zhí)行順序一致，主要注意的就是Lifecycle接口和SmartLifecycle接口，只有實現(xiàn)了SmartLifecycle接口的bean在初始化時才會被自動調(diào)用，而實現(xiàn)了Lifecycle接口的除非顯式調(diào)用start和stop方法才會被調(diào)用。
總結(jié)
到此這篇關(guān)于Spring與bean有關(guān)的生命周期的文章就介紹到這了,更多相關(guān)Spring與bean生命周期內(nèi)容請搜索服務(wù)器之家以前的文章或繼續(xù)瀏覽下面的相關(guān)文章希望大家以后多多支持服務(wù)器之家！
原文鏈接：https://www.cnblogs.com/eaglelihh/p/13383039.html
