springMvc源码大致过程

web.xml加载DispatcherServlet（子类兼有自己特性还有父类所有的特性，若有覆盖方法的用子类自己的，父类的某个方法有入口作用

那么如果用子类的话（子类 覆盖了这个方法）子类的这个方法也就有了入口特性）

 

源配入口

 

DispatcherServlet--》应用上下文初始化--》执行转发--》通过各种拦截器--》最终跳转

 

FrameworkServlet

  public void onApplicationEvent(ContextRefreshedEvent event)

  {

    this.refreshEventReceived = true;

    onRefresh(event.getApplicationContext());

  }

  

  protected void onRefresh(ApplicationContext context) {}///框架在写接口时会自己先写一个抽象的供自己调用，后面有子类继承他的时候覆写这个方法就会在子类中

  调用这个具体方法了

  

 

 

  DispatcherServlet

 

 protected void onRefresh(ApplicationContext context)

  {

    initStrategies(context);

  }

 

  protected void initStrategies(ApplicationContext context)

  {

    initMultipartResolver(context);

    initLocaleResolver(context);

    initThemeResolver(context);

    initHandlerMappings(context);

    initHandlerAdapters(context);

    initHandlerExceptionResolvers(context);

    initRequestToViewNameTranslator(context);

    initViewResolvers(context);

    initFlashMapManager(context);

  }

 

 

 

 

 

protected void doService(HttpServletRequest request, HttpServletResponse response)

    throws Exception

  {

  

  

    doDispatch(request, response);

 

 

  }

 

 protected void doDispatch(HttpServletRequest request, HttpServletResponse response)

    throws Exception

  {

 mappedHandler.applyPostHandle(processedRequest, response, mv);

 processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);

 

}

 

 

 

  private void processDispatchResult(HttpServletRequest request, HttpServletResponse response, HandlerExecutionChain mappedHandler, ModelAndView mv, Exception exception)

    throws Exception

  {

    boolean errorView = false;

    if (exception != null) {

      if ((exception instanceof ModelAndViewDefiningException))

      {

        this.logger.debug("ModelAndViewDefiningException encountered", exception);

        mv = ((ModelAndViewDefiningException)exception).getModelAndView();

      }

      else

      {

        Object handler = mappedHandler != null ? mappedHandler.getHandler() : null;

        mv = processHandlerException(request, response, handler, exception);

        errorView = mv != null;

      }

    }

    if ((mv != null) && (!mv.wasCleared()))

    {

      render(mv, request, response);

      if (errorView) {

        WebUtils.clearErrorRequestAttributes(request);

      }

    }

    else if (this.logger.isDebugEnabled())

    {

      this.logger.debug("Null ModelAndView returned to DispatcherServlet with name '" + getServletName() + "': assuming HandlerAdapter completed request handling");

    }

    if (WebAsyncUtils.getAsyncManager(request).isConcurrentHandlingStarted()) {

      return;

    }

    if (mappedHandler != null) {

      mappedHandler.triggerAfterCompletion(request, response, null);

    }

  }