public class ContextLoaderListener implements ServletContextListener ...{   
  
  private ContextLoader contextLoader;   
  
  /**//**  
   * Initialize the root web application context.  
   */  
//当WEB上下文初始化时,系统会调用此方法   
  public void contextInitialized(ServletContextEvent event) ...{   
    this.contextLoader = createContextLoader();   
  
<span style="color:red;">   
    //监听到WEB上下文初始化的时候执行SPRING上下文contextLoader的初始化工作   
    this.contextLoader.initWebApplicationContext(event.getServletContext());   
</span>   
  }   
  
  /**//**  
   * Create the ContextLoader to use. Can be overridden in subclasses.  
   * @return the new ContextLoader  
   */  
  protected ContextLoader createContextLoader() ...{   
    return new ContextLoader();   
  }   
  
  /**//**  
   * Return the ContextLoader used by this listener.  
   */  
  public ContextLoader getContextLoader() ...{   
    return contextLoader;   
  }   
  
  /**//**  
   * Close the root web application context.  
   */  
  public void contextDestroyed(ServletContextEvent event) ...{   
    if (this.contextLoader != null) ...{   
      this.contextLoader.closeWebApplicationContext(event.getServletContext());   
    }   
  }   
  
}