public WebApplicationContext initWebApplicationContext(ServletContext servletContext)   
      throws IllegalStateException, BeansException ...{   
  
    if (servletContext.getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE) != null) ...{   
      throw new IllegalStateException(   
          "Cannot initialize context because there is already a root application context   
 
present - " +   
          "check whether you have multiple ContextLoader* definitions in your web.xml!");   
    }   
  
    long startTime = System.currentTimeMillis();   
    if (logger.isInfoEnabled()) ...{   
      logger.info("Root WebApplicationContext: initialization started");   
    }   
    servletContext.log("Loading Spring root WebApplicationContext");   
  
    try ...{   
      // Determine parent for root web application context, if any.   
      ApplicationContext parent = loadParentContext(servletContext);   
  
      // Store context in local instance variable, to guarantee that   
      // it is available on ServletContext shutdown.   
  
<span style="color:red;">   
      //创建web上下文   
      this.context = createWebApplicationContext(servletContext, parent);   
      servletContext.setAttribute(   
          WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, this.context);   
</span>   
  
      if (logger.isInfoEnabled()) ...{   
        logger.info("Using context class [" + this.context.getClass().getName() +   
            "] for root WebApplicationContext");   
      }   
      if (logger.isDebugEnabled()) ...{   
        logger.debug("Published root WebApplicationContext [" + this.context +   
            "] as ServletContext attribute with name [" +   
            WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE + "]");   
      }   
      if (logger.isInfoEnabled()) ...{   
        long elapsedTime = System.currentTimeMillis() - startTime;   
        logger.info("Root WebApplicationContext: initialization completed in " + elapsedTime + "   
 
ms");   
      }   
  
      return this.context;   
    }   
    catch (RuntimeException ex) ...{   
      logger.error("Context initialization failed", ex);   
      servletContext.setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, ex);   
      throw ex;   
    }   
    catch (Error err) ...{   
      logger.error("Context initialization failed", err);   
      servletContext.setAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE, err);   
      throw err;   
    }   
  }