spring-context解析--容器构造方法

结论

package com.springdemo.demo.interfac;

import com.springdemo.demo.interfac.ee.BB;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Lazy;

@Configuration
@ComponentScan("com.springdemo.demo.interfac")
public class Demo {
    public static void main(String[] args) {
        AnnotationConfigApplicationContext annotationConfigApplicationContext = new AnnotationConfigApplicationContext(Demo.class);
        Lazy annotation = BB.class.getAnnotation(Lazy.class);
        if (annotation == null){
            BB bb = annotationConfigApplicationContext.getBean(BB.class);
            bb.say();
        }
        Object environment = annotationConfigApplicationContext.getBean("environment");
        System.out.println(environment);

    }
}

register方法

• 优先注册启动类(Demo.class)
  将这个启动类bean注册到AnnotationConfigApplicationContext的reader(BeanDinfinitionRegister的包装类)属性中的,由reader属性来调用GenericApplicationContext中的doRegister，实际上还是在DefaultListableBeanFactory的beanDefinitionMap中
• 默认注册4个bean
  ConfigurationClassPostProcessor -> 处理@configuration
  AutowiredAnnotationBeanPostProcessor -> 处理@autowired、@Lookup、@Value 支持jsr-330@Inject
  CommonAnnotationBeanPostProcessor -> 提供@JSR-250的支持
  PersistenceAnnotationBeanPostProcessor -> 提供jpa支持
  EventListenerMethodProcessor -> 提供@EventListener的支持
  DefaultEventListenerFactory -> 提供@EventListener的支持

refresh方法

• 准备刷新（将早期监听器质空）-> 获取beanFactory-> 准备刷新容器（注入environment）环境bean、systemProperties（系统属性bean），systemEnvironment（系统环境bean)) -> 处理所有继承了BeanDefinitionRegistryPostProcessor的bean -> ``

@Override
    public void refresh() throws BeansException, IllegalStateException {
        synchronized (this.startupShutdownMonitor) {
            // Prepare this context for refreshing.
            prepareRefresh();

            // Tell the subclass to refresh the internal bean factory.
            ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

            // Prepare the bean factory for use in this context.
            prepareBeanFactory(beanFactory);

            try {
                // Allows post-processing of the bean factory in context subclasses.
                postProcessBeanFactory(beanFactory);

                // 处理所有的实现了`BeanDefinitionRegistryPostProcessor` 接口的processor
                invokeBeanFactoryPostProcessors(beanFactory);

                // 处理所有实现了`BeanPostProcessor`接口的processor
                registerBeanPostProcessors(beanFactory);

                //初始化信息源
                initMessageSource();

                //初始化事件多种转换器
                initApplicationEventMulticaster();

                // Initialize other special beans in specific context subclasses.
                onRefresh();

                //注册所有实现了ApplicationListener的监听器
                registerListeners();

                // Instantiate all remaining (non-lazy-init) singletons.
                finishBeanFactoryInitialization(beanFactory);

                // Last step: publish corresponding event.
                finishRefresh();
            }

            catch (BeansException ex) {
                if (logger.isWarnEnabled()) {
                    logger.warn("Exception encountered during context initialization - " +
                            "cancelling refresh attempt: " + ex);
                }

                // Destroy already created singletons to avoid dangling resources.
                destroyBeans();

                // Reset 'active' flag.
                cancelRefresh(ex);

                // Propagate exception to caller.
                throw ex;
            }

            finally {
                // Reset common introspection caches in Spring's core, since we
                // might not ever need metadata for singleton beans anymore...
                resetCommonCaches();
            }
        }
    }