SpringMVC的流程 | 易学教程

起点：tomcat调用FrameworkServlet的service(ServletRequest req, ServletResponse res)方法：
1）FrameworkServlet的service(ServletRequest req, ServletResponse res) 方法转到2）
2）HttpServlet的service(ServletRequest req, ServletResponse res) 方法转到3）
3）FrameworkServlet的doGet(HttpServletRequest request, HttpServletResponse response) 方法转到4）
4）FrameworkServlet的processRequest(HttpServletRequest request, HttpServletResponse response) 方法转到5）
5）DispatcherServlet的doService(HttpServletRequest request, HttpServletResponse response) 方法转到6）
6）DispatcherServlet的doDispatch(HttpServletRequest request, HttpServletResponse response)//重点来依次调用7）8）9）10)
6.1）mappedHandler = getHandler(processedRequest);//利用7）
6.2）HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());//利用8）
6.3）mv = ha.handle(processedRequest, response, mappedHandler.getHandler());//利用9）和6.1）、6.2）的返回值
6.4）processDispatchResult(processedRequest, response, mappedHandler, mv, dispatchException);//

7）DispatcherServlet的 HandlerExecutionChain getHandler(HttpServletRequest request)//找HandlerExecutionChain
7.1）属性List<HandlerMapping> handlerMappings;
7.2）HandlerExecutionChain handler = hm.getHandler(request);//内部执行7.2）
7.3）HandlerMethod getHandlerInternal(HttpServletRequest request);//内部执行7.3）
7.4）HandlerMethod lookupHandlerMethod(String lookupPath, HttpServletRequest request);//通过请求的路径，找到HandlerMethod

8）DispatcherServlet的 HandlerAdapter getHandlerAdapter(Object handler)//传入的是HandlerExecutionChain的handler
8.1）属性List<HandlerAdapter> handlerAdapters;//通过判断8.2）返回一个
8.2）ha.supports(handler);//如果成功，返回ha

9）ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler);//返回ModelAndView
9.1）ModelAndView handleInternal(HttpServletRequest request,HttpServletResponse response, HandlerMethod handlerMethod)
9.2）ModelAndView invokeHandlerMethod(HttpServletRequest request,HttpServletResponse response, HandlerMethod handlerMethod)
9.3）ModelAndView getModelAndView(ModelAndViewContainer mavContainer,ModelFactory modelFactory, NativeWebRequest webRequest)

10)processDispatchResult(HttpServletRequest request, HttpServletResponse response,HandlerExecutionChain mappedHandler, ModelAndView mv, Exception exception)//获得ModelAndView的view，并渲染
10.1）render(mv, request, response);//
10.2）render(ModelAndView mv, HttpServletRequest request, HttpServletResponse response)//
10.3）view = mv.getView();//获取view
10.4）view.render(mv.getModelInternal(), request, response);//渲染
在这里插入图片描述
总结：前面几部不重要，重要的是第6）步
1）获取HandlerExecutionChain{handler，interceptorList，interceptors};//通过遍历handlerMappings，获取HandlerExecutionChain
2）使用HandlerExecutionChain的handler，获取HandlerAdapter;//遍历handlerAdapters
3）使用HandlerAdapter通过HandlerExecutionChain得到ModelAndView
4）执行processDispatchResult，获取ModelAndView的View并渲染

名词解释：
handlermapping：处理器映射
HandlerAdapter：适配器

//非启动时执行，第一次时查询

protected void initStrategies(ApplicationContext context) {
	initMultipartResolver(context);
	initLocaleResolver(context);
	initThemeResolver(context);
	initHandlerMappings(context);
	initHandlerAdapters(context);
	initHandlerExceptionResolvers(context);
	initRequestToViewNameTranslator(context);
	initViewResolvers(context);
	initFlashMapManager(context);
}

来源：CSDN

作者：孤竹彧

链接：https://blog.csdn.net/qq_33321609/article/details/104885553

标签

modelandview

handler

response

request