SpringMVC源码阅读(三)

先理一下Bean的初始化路线

org.springframework.beans.factory.support.AbstractBeanDefinitionReader

public int loadBeanDefinitions(Resource... resources) throws BeanDefinitionStoreException
{
    Assert.notNull(resources, "Resource array must not be null");
    int counter = 0;
    for (Resource resource : resources) {
      counter += loadBeanDefinitions(resource);
    }
    return counter;
}

org.springframework.beans.factory.xml.XmlBeanDefinitionReader

public int loadBeanDefinitions(Resource resource)
    throws BeanDefinitionStoreException
  {
    return loadBeanDefinitions(new EncodedResource(resource));
  }

protected int doLoadBeanDefinitions(InputSource inputSource, Resource resource)
    throws BeanDefinitionStoreException
  {
    try
    {
      int validationMode = getValidationModeForResource(resource);
      Document doc = this.documentLoader.loadDocument(inputSource, getEntityResolver(), this.errorHandler, validationMode, isNamespaceAware());

      return registerBeanDefinitions(doc, resource);
    }
    catch (BeanDefinitionStoreException ex) {
      throw ex;
    }
    catch (SAXParseException ex) {
      throw new XmlBeanDefinitionStoreException(resource.getDescription(), "Line " + ex.getLineNumber() + " in XML document from " + resource + " is invalid", ex);
    }
    catch (SAXException ex)
    {
      throw new XmlBeanDefinitionStoreException(resource.getDescription(), "XML document from " + resource + " is invalid", ex);
    }
    catch (ParserConfigurationException ex)
    {
      throw new BeanDefinitionStoreException(resource.getDescription(), "Parser configuration exception parsing XML from " + resource, ex);
    }
    catch (IOException ex)
    {
      throw new BeanDefinitionStoreException(resource.getDescription(), "IOException parsing XML document from " + resource, ex);
    }
    catch (Throwable ex)
    {
      throw new BeanDefinitionStoreException(resource.getDescription(), "Unexpected exception parsing XML document from " + resource, ex);
    }
  }

org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader

 protected void parseBeanDefinitions(Element root, BeanDefinitionParserDelegate delegate)
  {
    if (delegate.isDefaultNamespace(root)) {
      NodeList nl = root.getChildNodes();
      for (int i = 0; i < nl.getLength(); i++) {
        Node node = nl.item(i);
        if ((node instanceof Element)) {
          Element ele = (Element)node;
          if (delegate.isDefaultNamespace(ele)) {
            parseDefaultElement(ele, delegate);
          }
          else {
            delegate.parseCustomElement(ele);
          }
        }
      }
    }
    else {
      delegate.parseCustomElement(root);
    }
  }