# Default WebApplicationContext implementation class for ContextLoader.   
# Used as fallback when no explicit context implementation has been specified as
    context-param.   
# Not meant to be customized by application developers.   
  
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#默认的WebApplicationContext为org.springframework.web.context.support.
     XmlWebApplicationContext   
org.springframework.web.context.WebApplicationContext=org.springframework.web.
    context.support.XmlWebApplicationContext   
</span>  

public class XmlWebApplicationContext extends 
             AbstractRefreshableWebApplicationContext ...{   
  
  /**//** Default config location for the root context */  
  
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  //配置了默认的spring配置文件   
  public static final String DEFAULT_CONFIG_LOCATION = "/WEB-INF/applicationContext.xml";   
</span>   
  
  //配置文件默认BUILD路径   
  public static final String DEFAULT_CONFIG_LOCATION_PREFIX = "/WEB-INF/";   
  
  //配置文件默认后缀名   
  public static final String DEFAULT_CONFIG_LOCATION_SUFFIX = ".xml";   
  
  /**//**  
   * Loads the bean definitions via an XmlBeanDefinitionReader.  
   * @see org.springframework.beans.factory.xml.XmlBeanDefinitionReader  
   * @see #initBeanDefinitionReader  
   * @see #loadBeanDefinitions  
   */  
  //获得bean配置   
  protected void loadBeanDefinitions(DefaultListableBeanFactory beanFactory) throws 
            IOException ...{   
    //从BEAN工厂获得一个XmlBeanDefinitionReader 来读取SPRING配置文件   
    XmlBeanDefinitionReader beanDefinitionReader = new 
                  XmlBeanDefinitionReader(beanFactory);   
  
    //设置beanDefinitionReader服务于当前CONTEXT   
    // resource loading environment.   
    beanDefinitionReader.setResourceLoader(this);   
    beanDefinitionReader.setEntityResolver(new ResourceEntityResolver(this));   
  
    // Allow a subclass to provide custom initialization of the reader,   
    // then proceed with actually loading the bean definitions.   
    initBeanDefinitionReader(beanDefinitionReader);   
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    //读取配置文件   
    loadBeanDefinitions(beanDefinitionReader);   
</span>   
  }   
  
  /**//**  
   * Initialize the bean definition reader used for loading the bean  
   * definitions of this context. Default implementation is empty.  
   * <p>Can be overridden in subclasses, e.g. for turning off XML validation  
   * or using a different XmlBeanDefinitionParser implementation.  
   * @param beanDefinitionReader the bean definition reader used by this context  
   * @see org.springframework.beans.factory.xml.XmlBeanDefinitionReader#setValidationMode  
   * @see org.springframework.beans.factory.xml.XmlBeanDefinitionReader
                  #setDocumentReaderClass  
   */  
  protected void initBeanDefinitionReader(XmlBeanDefinitionReader 
                  beanDefinitionReader) ...{   
  }   
  
  /**//**  
   * Load the bean definitions with the given XmlBeanDefinitionReader.  
   * <p>The lifecycle of the bean factory is handled by the refreshBeanFactory method;  
   * therefore this method is just supposed to load and/or register bean definitions.  
   * <p>Delegates to a ResourcePatternResolver for resolving location patterns  
   * into Resource instances.  
   * @throws org.springframework.beans.BeansException in case of bean registration errors  
   * @throws java.io.IOException if the required XML document isn't found  
   * @see #refreshBeanFactory  
   * @see #getConfigLocations  
   * @see #getResources  
   * @see #getResourcePatternResolver  
   */  
<span style="color:red;">   
  //读取配置文件   
  protected void loadBeanDefinitions(XmlBeanDefinitionReader reader) throws 
          BeansException, IOException ...{   
    String[] configLocations = getConfigLocations();   
    if (configLocations != null) ...{   
      for (int i = 0; i < configLocations.length; i++) ...{   
        reader.loadBeanDefinitions(configLocations[i]);   
      }   
    }   
  }   
</span>   
  
  /**//**  
   * The default location for the root context is "/WEB-INF/applicationContext.xml",  
   * and "/WEB-INF/test-servlet.xml" for a context with the namespace "test-servlet"  
   * (like for a DispatcherServlet instance with the servlet-name "test").  
   */  
  //获得默认的ConfigLocations   
  protected String[] getDefaultConfigLocations() ...{   
    if (getNamespace() != null) ...{   
      return new String[] ...{DEFAULT_CONFIG_LOCATION_PREFIX + getNamespace() +    
  
DEFAULT_CONFIG_LOCATION_SUFFIX};   
    }   
    else ...{   
      return new String[] ...{DEFAULT_CONFIG_LOCATION};   
    }   
  }