Spring多种加载Bean方式解析

<bean id="dictionaryRelMap" class="java.util.HashMap"/>

@Component
public class xxxServicer{
 ....
}

@Configuration
public class xxxConfiguration{
 @Bean
 public myBean myBean(){
   return new myBean();
 }
}

@Override
public BeanDefinition parse(Element element, ParserContext parserContext) {
    //获取base-package标签
  String basePackage = element.getAttribute(BASE_PACKAGE_ATTRIBUTE);
  basePackage = parserContext.getReaderContext().getEnvironment().resolvePlaceholders(basePackage);
  String[] basePackages = StringUtils.tokenizeToStringArray(basePackage,
      ConfigurableApplicationContext.CONFIG_LOCATION_DELIMITERS);

  // 实际处理类是ClassPathBeanDefinitionScanner 
  ClassPathBeanDefinitionScanner scanner = configureScanner(parserContext, element);
  //扫描basePackage下所有的类，如果有@Component等标签就是注册到Spring中
  Set<BeanDefinitionHolder> beanDefinitions = scanner.doScan(basePackages);
  registerComponents(parserContext.getReaderContext(), beanDefinitions, element);
  return null;
}

private void loadBeanDefinitionsForConfigurationClass(ConfigurationClass configClass,
    TrackedConditionEvaluator trackedConditionEvaluator) {

    //如果自己是通过@Import注解定义的，那么需要把自己注册到Spring中
  if (configClass.isImported()) {
    registerBeanDefinitionForImportedConfigurationClass(configClass);
  }
  //这里就是处理方法上的@Bean
  for (BeanMethod beanMethod : configClass.getBeanMethods()) {
    loadBeanDefinitionsForBeanMethod(beanMethod);
  }
  //处理@ImportResource，里面解析xml就是上面说到的解析xml的XmlBeanDefinitionReader
  loadBeanDefinitionsFromImportedResources(configClass.getImportedResources());
  loadBeanDefinitionsFromRegistrars(configClass.getImportBeanDefinitionRegistrars());
}

 @Override
 public void preInstantiateSingletons() throws BeansException {
   for (String beanName : beanNames) {
    RootBeanDefinition bd = getMergedLocalBeanDefinition(beanName);
    if (!bd.isAbstract() && bd.isSingleton() && !bd.isLazyInit()) {
      if (isFactoryBean(beanName)) {
        final FactoryBean<?> factory = (FactoryBean<?>) getBean(FACTORY_BEAN_PREFIX + beanName);
        boolean isEagerInit;
        if (System.getSecurityManager() != null && factory instanceof SmartFactoryBean) {
          isEagerInit = AccessController.doPrivileged(new PrivilegedAction<Boolean>() {
            @Override
            public Boolean run() {
              return ((SmartFactoryBean<?>) factory).isEagerInit();
            }
          }, getAccessControlContext());
        }
        else {
          isEagerInit = (factory instanceof SmartFactoryBean &&
                ((SmartFactoryBean<?>) factory).isEagerInit());
        }
        if (isEagerInit) {
          getBean(beanName);
        }
      }
      else {
        getBean(beanName);
      }
    }
  }
}

protected Object initializeBean(final String beanName, final Object bean, RootBeanDefinition mbd) {
  //处理xxAware接口
  if (System.getSecurityManager() != null) {
    AccessController.doPrivileged(new PrivilegedAction<Object>() {
      @Override
      public Object run() {
        invokeAwareMethods(beanName, bean);
        return null;
      }
    }, getAccessControlContext());
  }
  else {
    invokeAwareMethods(beanName, bean);
  }
  Object wrappedBean = bean;
  if (mbd == null || !mbd.isSynthetic()) {
    // 调用BeanPostProcessors#postProcessBeforeInitialization
    wrappedBean = applyBeanPostProcessorsBeforeInitialization(wrappedBean, beanName);
  }
  try {
    //初始化，先判断是否是InitializingBean，
    invokeInitMethods(beanName, wrappedBean, mbd);
  }
  catch (Throwable ex) {
    throw new BeanCreationException(
        (mbd != null ? mbd.getResourceDescription() : null),
        beanName, "Invocation of init method failed", ex);
  }
  if (mbd == null || !mbd.isSynthetic()) {
    // 调用BeanPostProcessors#postProcessAfterInitialization
    wrappedBean = applyBeanPostProcessorsAfterInitialization(wrappedBean, beanName);
  }
  return wrappedBean;
}