Beanfactory creation process

1、 obtain BeanFactory Sub process

2、BeanDefinition Load analysis and registration sub process  

2.1、 This sub process involves the following key steps

Resource location ： Pointing right BeanDefinition Resource location process . Generally speaking, it is to find the definition Javabean The information of XML file , And encapsulate it as Resource object .

BeanDefinition load ： User defined Javabean Expressed as IoC The data structure inside the container , The data structure inside the container is BeanDefinition.

register BeanDefinition To IoC Containers

2.2、 process analysis  

Step 1： Sub process entry AbstractRefreshableApplicationContext#refreshBeanFactory In the method

 

Step 2： Calling multiple classes in turn loadBeanDefinitions Method —> AbstractXmlApplicationContext —>      
AbstractBeanDefinitionReader —> XmlBeanDefinitionReader Until XmlBeanDefinitionReader Of doLoadBeanDefinitions Method

 

Step 3： We focus on XmlBeanDefinitionReader Class registerBeanDefinitions Method , Multiple overloaded calls occurred during , Let's go to the last  

Here we focus on two places ：⼀ individual createRederContext Method ,⼀ Yes DefaultBeanDefinitionDocumentReader Class registerBeanDefinitions Method , Enter the first createRederContext Methods take a look at  

We can see , here Spring ⾸ It's done first NamespaceHandlerResolver The initialization .

Let's go back to registerBeanDefinitions Method to track , Called DefaultBeanDefinitionDocumentReader#registerBeanDefinitions Method

Get into doRegisterBeanDefinitions Method

Get into parseBeanDefinitions Method

Get into parseDefaultElement Method

Get into processBeanDefinition Method

thus , End of registration process , We found that , The so-called registration is to encapsulate XML As defined in Bean The information is encapsulated as BeanDefinition Put after object ⼀ individual Map in ,BeanFactory In order to Map The structure of organizing these BeanDefinition Of . 

Can be in DefaultListableBeanFactory See this in Map The definition of

/** Map of bean definition objects, keyed by bean name. */
private final Map<String, BeanDefinition> beanDefinitionMap = new ConcurrentHashMap<>(256);

2.3、 Sequence diagram