spring框架源码十五、BeanFactory创建子流程

refresh()方法标志着spring容器启动过程开始，

它主要做两件事：
创建工厂、实例化bean对象。

ClassPathXmlApplicationContext

ClassPathXmlApplicationContext#ClassPathXmlApplicationContext(java.lang.String)

ClassPathXmlApplicationContext#ClassPathXmlApplicationContext(java.lang.String[], boolean, org.springframework.context.ApplicationContext)

AbstractApplicationContext#refresh

BeanFactory创建子流程

AbstractApplicationContext#obtainFreshBeanFactory

// 获取BeanFactory
// 加载BeanDefinition并注册到BeanDefinitionRegistry去
// Tell the subclass to refresh the internal bean factory.
ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

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获取BeanFactory

	/**
	 * This implementation performs an actual refresh of this context's underlying
	 * bean factory, shutting down the previous bean factory (if any) and
	 * initializing a fresh bean factory for the next phase of the context's lifecycle.
	 */
	@Override
	protected final void refreshBeanFactory() throws BeansException {
		// 判断是否有BeanFactory
		if (hasBeanFactory()) {
			// 销毁Beans
			destroyBeans();
			// 关闭BeanFactory
			closeBeanFactory();
		}
		try {
			// 实例化DefaultListableBeanFactory
			DefaultListableBeanFactory beanFactory = createBeanFactory();
			// 设置序列化ID
			beanFactory.setSerializationId(getId());
			// 定义BeanFactory的一些属性（是否允许覆盖、是否允许循环依赖）
			customizeBeanFactory(beanFactory);
			// ## 加载BeanDefinitions
			loadBeanDefinitions(beanFactory);
			this.beanFactory = beanFactory;
		}
		catch (IOException ex) {
			throw new ApplicationContextException("I/O error parsing bean definition source for " + getDisplayName(), ex);
		}
	}
	
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如果你不知道它执行的是哪个类中的实现，debug！

穷且益坚，不坠青云之志，
老当益壮，宁移白首之心。
与诸位共勉！