Spring源码解析-实例化bean对象

  

  spring加载配置文件,AbstractApplicationContext类中的refresh方法起着重要的作用。

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

            // Tell the subclass to refresh the internal bean factory.刷新子类beanFactory,注册beanDefinition
            ConfigurableListableBeanFactory beanFactory = obtainFreshBeanFactory();

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

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

                // Invoke factory processors registered as beans in the context.
                invokeBeanFactoryPostProcessors(beanFactory);

                // Register bean processors that intercept bean creation.
                registerBeanPostProcessors(beanFactory);

                // Initialize message source for this context.
                initMessageSource();

                // Initialize event multicaster for this context.
                initApplicationEventMulticaster();

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

                // Check for listener beans and register them.
                registerListeners();

                // Instantiate all remaining (non-lazy-init) singletons.初始化非懒加载的bean实例
                finishBeanFactoryInitialization(beanFactory);

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

            catch (BeansException ex) {
                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;
            }
        }
    }

实例化bean对象,主要的是在

finishBeanFactoryInitialization(beanFactory)

 方法。
大致的流程图(下部分):

 

点击查看大图

下面分析实例化bean对象的源码分析

加载bean对象:

 

AbstractBeanFactory类中,根据不同scope进行实例化,例如Singleton,Prototype

 

 

 

 

 

 

根据不同情况采用不同的代理方式:

到这里就是bean实例的初始化,可以看到spring采用的代理方式,来实现bean的初始化。

 

posted @ 2017-10-15 00:21  lzyer  阅读(2391)  评论(0编辑  收藏  举报