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Spring5源码 - 06 Spring Bean 生命周期流程 概述 01
接上文
通俗流程
下面说个比较常见的主干流程
实例化Bean对象，这个时候Bean的对象是非常低级的，基本不能够使用，因为连最基本的属性都没有设置，可以理解为
连Autowired注解都是没有解析的；
填充属性，当做完这一步，Bean对象基本是完整的了，可以理解为Autowired注解已经解析完毕，依赖注入完成了；
如果Bean实现了BeanNameAware接口，则调用setBeanName方法；
如果Bean实现了BeanClassLoaderAware接口，则调用setBeanClassLoader方法；
如果Bean实现了BeanFactoryAware接口，则调用setBeanFactory方法；
调用BeanPostProcessor的postProcessBeforeInitialization方法；
如果Bean实现了InitializingBean接口，调用afterPropertiesSet方法；
如果Bean定义了init-method方法，则调用Bean的init-method方法；
调用BeanPostProcessor的postProcessAfterInitialization方法；当进行到这一步，Bean已经被准备就绪了，一直停留在应用的
上下文中，直到被销毁；
如果应用的上下文被销毁了，如果Bean实现了DisposableBean接口，则调用destroy方法，如果Bean定义了destory-method
声明了销毁方法也会被调用。
finishBeanFactoryInitialization
完成Bean的初始化
/** * Finish the initialization of this context's bean factory, * initializing all remaining singleton beans. */ protected void finishBeanFactoryInitialization(ConfigurableListableBeanFactory beanFactory) { // bean工厂创建类型转化器 Convert /** * public class String2DateConversionService implements Converter<String,Date> { public Date convert(String source) { SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); try { return sdf.parse(source); } catch (ParseException e) { return null; } } } @Bean public ConversionServiceFactoryBean conversionService() { ConversionServiceFactoryBean factoryBean = new ConversionServiceFactoryBean(); Set<Converter> converterSet = new HashSet<Converter>(); converterSet.add(new String2DateConversionService()); factoryBean.setConverters(converterSet); return factoryBean; } ConversionServiceFactoryBean conversionServiceFactoryBean = (ConversionServiceFactoryBean) ctx.getBean(ConversionServiceFactoryBean.class); conversionServiceFactoryBean.getObject().convert("2019-06-03 12:00:00",Date.class) */ if (beanFactory.containsBean(CONVERSION_SERVICE_BEAN_NAME) && beanFactory.isTypeMatch(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class)) { beanFactory.setConversionService( beanFactory.getBean(CONVERSION_SERVICE_BEAN_NAME, ConversionService.class)); } /** * public class MainConfig implements EmbeddedValueResolverAware{ * * public void setEmbeddedValueResolver(StringValueResolver resolver) { this.jdbcUrl = resolver.resolveStringValue("${ds.jdbcUrl}"); this.classDriver = resolver.resolveStringValue("${ds.classDriver}"); } } */ if (!beanFactory.hasEmbeddedValueResolver()) { beanFactory.addEmbeddedValueResolver(strVal -> getEnvironment().resolvePlaceholders(strVal)); } // 处理aspectj String[] weaverAwareNames = beanFactory.getBeanNamesForType(LoadTimeWeaverAware.class, false, false); for (String weaverAwareName : weaverAwareNames) { getBean(weaverAwareName); } // Stop using the temporary ClassLoader for type matching. beanFactory.setTempClassLoader(null); //冻结所有的 bean 定义 ， 说明注册的 bean 定义将不被修改或任何进一步的处理 beanFactory.freezeConfiguration(); //实例化剩余的单实例bean beanFactory.preInstantiateSingletons(); }
继续
beanFactory.preInstantiateSingletons();
@Override public void preInstantiateSingletons() throws BeansException { if (logger.isDebugEnabled()) { logger.debug("Pre-instantiating singletons in " + this); } //获取我们容器中所有bean定义的名称 List<String> beanNames = new ArrayList<>(this.beanDefinitionNames); //循环我们所有的bean定义名称 for (String beanName : beanNames) { //合并我们的bean定义 RootBeanDefinition bd = getMergedLocalBeanDefinition(beanName); /** * 根据bean定义判断是不是抽象的&& 不是单例的 &&不是懒加载的 */ if (!bd.isAbstract() && bd.isSingleton() && !bd.isLazyInit()) { //是不是工厂bean if (isFactoryBean(beanName)) { //是的话 给beanName+前缀&符号 Object bean = getBean(FACTORY_BEAN_PREFIX + beanName); if (bean instanceof FactoryBean) { final FactoryBean<?> factory = (FactoryBean<?>) bean; boolean isEagerInit; if (System.getSecurityManager() != null && factory instanceof SmartFactoryBean) { isEagerInit = AccessController.doPrivileged((PrivilegedAction<Boolean>) ((SmartFactoryBean<?>) factory)::isEagerInit, getAccessControlContext()); } else { isEagerInit = (factory instanceof SmartFactoryBean && ((SmartFactoryBean<?>) factory).isEagerInit()); } //调用真正的getBean的流程 if (isEagerInit) { getBean(beanName); } } } else {//非工厂Bean 就是普通的bean getBean(beanName); } } } //或有的bean的名称 ...........到这里所有的单实例的bean已经记载到单实例bean到缓存中 for (String beanName : beanNames) { //从单例缓存池中获取所有的对象 Object singletonInstance = getSingleton(beanName); //判断当前的bean是否实现了SmartInitializingSingleton接口 if (singletonInstance instanceof SmartInitializingSingleton) { final SmartInitializingSingleton smartSingleton = (SmartInitializingSingleton) singletonInstance; if (System.getSecurityManager() != null) { AccessController.doPrivileged((PrivilegedAction<Object>) () -> { smartSingleton.afterSingletonsInstantiated(); return null; }, getAccessControlContext()); } else { //触发实例化之后的方法afterSingletonsInstantiated smartSingleton.afterSingletonsInstantiated(); } } } }
重点方法肯定是 getBean(beanName);咯
