Spring中重要的核心类和设计理念

　　Spring中又两个看着相似的接口，BeanFactory,FactoryBean，它们到底有什么作用和区别呢？

　　Spring中管理的Bean是由什么类解析呢？答案就是BeanFactory。

　　打开AbstractApplicationContext类，看refresh方法：

public void refresh() throws BeansException, IllegalStateException {
       synchronized(this.startupShutdownMonitor) {
           this.prepareRefresh();
           ConfigurableListableBeanFactory beanFactory = this.obtainFreshBeanFactory();
           this.prepareBeanFactory(beanFactory);
 
           try {
               this.postProcessBeanFactory(beanFactory);
               this.invokeBeanFactoryPostProcessors(beanFactory);
               this.registerBeanPostProcessors(beanFactory);
               this.initMessageSource();
               this.initApplicationEventMulticaster();
               this.onRefresh();
               this.registerListeners();<br>　　　　　　　　　　// 创建BeanFactory,就相当于创建一个汽车制造厂。
               this.finishBeanFactoryInitialization(beanFactory);
               this.finishRefresh();
           } catch (BeansException var9) {
               if (this.logger.isWarnEnabled()) {
                   this.logger.warn("Exception encountered during context initialization - cancelling refresh attempt: " + var9);
               }
 
               this.destroyBeans();
               this.cancelRefresh(var9);
               throw var9;
           } finally {
               this.resetCommonCaches();
           }
       }
   }