Spring学习笔记(一)——IOC

AbstractApplicationContext中会初始化resourcePatternResolver，默认是org.springframework.core.io.support.PathMatchingResourcePatternResolver.setConfigLocations(configLocations);

ApplicationContext初始化主要函数:

org.springframework.context.support.AbstractApplicationContext.refresh();

1. ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory()

将形如

<bean id=”a” class=”A”>

<property name=”prop1”>value1</property>

</bean>

转换成BeanDefinition，并存入DefaultListBeanFactory.beanDefinitionMap

并将构建好的beanFactory作为AbstractApplicationContext的属性

2. AbstractApplicationContext.prepareBeanFactory(ConfigurableListableBeanFactory beanFactory)

其中有步操作：beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));

这个ApplicationContextAwareProcessor是个BeanPostProcessor，负责注入ResourceLoaderAware, ApplicationEventPublisherAware, MessageSourceAware, ApplicationContextAware ApplicationContext相关特性的Bean.

if (bean instanceof ResourceLoaderAware) {

((ResourceLoaderAware) bean).setResourceLoader(this.applicationContext);

}

if (bean instanceof ApplicationEventPublisherAware) {

((ApplicationEventPublisherAware) bean).setApplicationEventPublisher(this.applicationContext);

}

if (bean instanceof MessageSourceAware) {

((MessageSourceAware) bean).setMessageSource(this.applicationContext);

}

if (bean instanceof ApplicationContextAware) {

((ApplicationContextAware) bean).setApplicationContext(this.applicationContext);

}

3. postProcessBeanFactory(beanFactory);

4. invokeBeanFactoryPostProcessors(beanFactory);

调用所有beanFactoryPostProcessor， BeanFactoryPostProcessor是一个接口，会处理beanfactory中的beanDefinition，实现此接口会被调用。

调用实现 PriorityOrdered接口的processor,并按priority排序调用

调用实现Ordered接口的processor,并按顺序调用。

最后调用其它实现BeanFactoryProcessor.

5. registerBeanPostProcessors(beanFactory);

将bean中所有的实现BeanPostProcessor接口的bean找到

如果有，先将BeanPostProcessorChecker加入数组

取得beanfactory中所有BeanPostProcessor

将其分组实现PriorityOrdered接口的，实现Ordered的接口，剩下的。

对PrioityOrded接口的进行排序并依次加入数组，

再将Orderd的加入，最后加入剩下的

6. initMessageSource();

寻找beanName为messageSource的bean,并初始化之。如果没有，初始化默认的。

7. initApplicationEventMulticaster();

寻找beanName为applicationEventMulticaster的bean，并初始化。如果没有，初始化默认的.在广播时寻找所有实现接口ApplicationListener的类。

8．onRefresh()

9. registerListeners()

注册所有实现接口ApplicationListener接口的类。

10. finishBeanFactoryInitialization(beanFactory)

初始化所有singlton的bean

Singleton创建方法：

org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(String, ObjectFactory)

化普通创建为Factory.getObject()方法

org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(String, RootBeanDefinition, Object[])

通过合适的方法找到时候的构造函数，初始化bean.并形成一个beanwrapper,并对每个属性进行Editor注册

a.调用构造函数

b.注入属性

org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.initializeBean(String, Object, RootBeanDefinition)

c.注入BeanFactory 感知环境的接口BeanNameAware,BeanClassLoaderAware,BeanFactoryAware

if (bean instanceof BeanNameAware) {

((BeanNameAware) bean).setBeanName(beanName);

}

if (bean instanceof BeanClassLoaderAware) {

((BeanClassLoaderAware) bean).setBeanClassLoader(getBeanClassLoader());

}

if (bean instanceof BeanFactoryAware) {

((BeanFactoryAware) bean).setBeanFactory(this);

}

d.调用BeanPostProcessors

applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);

采用责任链模式调用 BeanPostProcessor.ProcessBeforeInitialization(result, beanName)

e. 如果Bean实现了InitializingBean,调用afterPropertiesSet方法。

f.如果Bean具有init-method属性，调用init-method方法。

invokeCustomInitMethod(beanName, bean, initMethodName, mbd.isEnforceInitMethod());

g.最后调用BeanPostProcessors

applyBeanPostProcessorsAfterInitialization(wrappedBean,beanName);

采用责任链模式调用BeanPostProcessor.postProcessAfterInitialization(result, beanName)