Spring IOC源码(五)：IOC容器之 beanFactory准备工作

1、源码解析

　　prepareBeanFactory(beanFactory)是beanFactory的准备工作，主要是对beanFactory的各种属性做填充。

 1 // beanFactory的准备工作，配置容器上下文，如容器的类加载器和后置处理器
 2 protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
 3 
 4    // 设置当前context的classloader为beanFactory的classloader
 5    beanFactory.setBeanClassLoader(getClassLoader());
 6    // 设置表达式语言处理器
 7    beanFactory.setBeanExpressionResolver(new StandardBeanExpressionResolver(beanFactory.getBeanClassLoader()));
 8    // 为beanFactory增加一个默认的propertyEditor，这个主要是对bean的属性等设置管理的一个工具类
 9    beanFactory.addPropertyEditorRegistrar(new ResourceEditorRegistrar(this, getEnvironment()));
10 
11    // 添加beanPostProcessor,ApplicationContextAwareProcessor此类用来完成某些Aware对象的注入
12    beanFactory.addBeanPostProcessor(new ApplicationContextAwareProcessor(this));
13    // 设置要忽略自动装配的接口，这些接口的实现是由容器通过set方法进行注入的，所以在使用autowire进行注入的时候需要将这些接口进行忽略
14    beanFactory.ignoreDependencyInterface(EnvironmentAware.class);
15    beanFactory.ignoreDependencyInterface(EmbeddedValueResolverAware.class);
16    beanFactory.ignoreDependencyInterface(ResourceLoaderAware.class);
17    beanFactory.ignoreDependencyInterface(ApplicationEventPublisherAware.class);
18    beanFactory.ignoreDependencyInterface(MessageSourceAware.class);
19    beanFactory.ignoreDependencyInterface(ApplicationContextAware.class);
20 
21    // 设置几个自动装配的特殊规则,当在进行ioc初始化的如果有多个实现，那么就使用指定的对象进行注入
22    beanFactory.registerResolvableDependency(BeanFactory.class, beanFactory);
23    beanFactory.registerResolvableDependency(ResourceLoader.class, this);
24    beanFactory.registerResolvableDependency(ApplicationEventPublisher.class, this);
25    beanFactory.registerResolvableDependency(ApplicationContext.class, this);
26 
27    // 注册BeanPostProcessor, 在registerBeanPostProcessors做处理
28    beanFactory.addBeanPostProcessor(new ApplicationListenerDetector(this));
29 
30    // 增加对AspectJ的支持
31    if (beanFactory.containsBean(LOAD_TIME_WEAVER_BEAN_NAME)) {
32       beanFactory.addBeanPostProcessor(new LoadTimeWeaverAwareProcessor(beanFactory));
33       beanFactory.setTempClassLoader(new ContextTypeMatchClassLoader(beanFactory.getBeanClassLoader()));
34    }
35 
36    // 注册默认的环境信息到一级缓存中
37    if (!beanFactory.containsLocalBean(ENVIRONMENT_BEAN_NAME)) {
38       beanFactory.registerSingleton(ENVIRONMENT_BEAN_NAME, getEnvironment());
39    }
40    // 注册系统属性到容器的一级缓存中
41    if (!beanFactory.containsLocalBean(SYSTEM_PROPERTIES_BEAN_NAME)) {
42       beanFactory.registerSingleton(SYSTEM_PROPERTIES_BEAN_NAME, getEnvironment().getSystemProperties());
43    }
44    // 注册系统环境到容器的一级缓存中
45    if (!beanFactory.containsLocalBean(SYSTEM_ENVIRONMENT_BEAN_NAME)) {
46       beanFactory.registerSingleton(SYSTEM_ENVIRONMENT_BEAN_NAME, getEnvironment().getSystemEnvironment());
47    }
48 }