org.springframework.web.servlet.DispatcherServlet-doDispatch-handle执行介绍

###org.springframework.web.servlet.DispatcherServlet-doDispatch

/** * 4.预处理,行执行拦截器等 */ if (!mappedHandler.applyPreHandle(processedRequest, response)) { return; } /** * 5.实现执行Controller中(Handler)的方法,返回ModelAndView视图 */ // Actually invoke the handler. mv = ha.handle(processedRequest, response, mappedHandler.getHandler()); if (asyncManager.isConcurrentHandlingStarted()) { /** * 判断 是不是异步请求,是就返回了 */ return; }

走了org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter#handle

public final ModelAndView handle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { return handleInternal(request, response, (HandlerMethod) handler); }

handleInternal方法

org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter#invokeHandlerMethod

protected ModelAndView invokeHandlerMethod(HttpServletRequest request, HttpServletResponse response, HandlerMethod handlerMethod) throws Exception { ServletWebRequest webRequest = new ServletWebRequest(request, response); try { //获取全局配置的initBinder和当前 Handler-Controller中配置的initBinder用于数据绑定 WebDataBinderFactory binderFactory = getDataBinderFactory(handlerMethod); //获取所有ModelAttribute&&RequestMapping的方法,在具体的请求之前先执行 ModelFactory modelFactory = getModelFactory(handlerMethod, binderFactory); //将handlerMethod封装为ServletInvocableHandlerMethod ServletInvocableHandlerMethod invocableMethod = createInvocableHandlerMethod(handlerMethod); if (this.argumentResolvers != null) { //设置参数解析器 invocableMethod.setHandlerMethodArgumentResolvers(this.argumentResolvers); } if (this.returnValueHandlers != null) { //设置结果解析器 invocableMethod.setHandlerMethodReturnValueHandlers(this.returnValueHandlers); } invocableMethod.setDataBinderFactory(binderFactory); invocableMethod.setParameterNameDiscoverer(this.parameterNameDiscoverer); //创建 一个ModelAndViewContainer容器 ModelAndViewContainer mavContainer = new ModelAndViewContainer(); mavContainer.addAllAttributes(RequestContextUtils.getInputFlashMap(request)); //调用前的modelFactory中的方法 modelFactory.initModel(webRequest, mavContainer, invocableMethod); //设置是否重定向 mavContainer.setIgnoreDefaultModelOnRedirect(this.ignoreDefaultModelOnRedirect); //设置异常请求 AsyncWebRequest asyncWebRequest = WebAsyncUtils.createAsyncWebRequest(request, response); //异步请求超时时间 asyncWebRequest.setTimeout(this.asyncRequestTimeout); //Web异步管理器 WebAsyncManager asyncManager = WebAsyncUtils.getAsyncManager(request); //设置线程池 asyncManager.setTaskExecutor(this.taskExecutor); asyncManager.setAsyncWebRequest(asyncWebRequest); //回调拦截器 asyncManager.registerCallableInterceptors(this.callableInterceptors); asyncManager.registerDeferredResultInterceptors(this.deferredResultInterceptors); if (asyncManager.hasConcurrentResult()) { Object result = asyncManager.getConcurrentResult(); mavContainer = (ModelAndViewContainer) asyncManager.getConcurrentResultContext()[0]; asyncManager.clearConcurrentResult(); LogFormatUtils.traceDebug(logger, traceOn -> { String formatted = LogFormatUtils.formatValue(result, !traceOn); return "Resume with async result [" + formatted + "]"; }); invocableMethod = invocableMethod.wrapConcurrentResult(result); } //对请求参数进行处理,调用目标HandlerMethods方法,返回一个ModelAndView invocableMethod.invokeAndHandle(webRequest, mavContainer); if (asyncManager.isConcurrentHandlingStarted()) { //异步处理就直接返回 return null; } //返回ModelAndView,同步判断是否要重定向,还要将flashmanger设置 return getModelAndView(mavContainer, modelFactory, webRequest); } finally { webRequest.requestCompleted(); } }

org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod#invokeAndHandle

public void invokeAndHandle(ServletWebRequest webRequest, ModelAndViewContainer mavContainer, Object... providedArgs) throws Exception { //执行请求方法,返回结果 Object returnValue = invokeForRequest(webRequest, mavContainer, providedArgs); //设置返回状态 setResponseStatus(webRequest); if (returnValue == null) { if (isRequestNotModified(webRequest) || getResponseStatus() != null || mavContainer.isRequestHandled()) { disableContentCachingIfNecessary(webRequest); mavContainer.setRequestHandled(true); return; } } else if (StringUtils.hasText(getResponseStatusReason())) { mavContainer.setRequestHandled(true); return; } mavContainer.setRequestHandled(false); Assert.state(this.returnValueHandlers != null, "No return value handlers"); try { this.returnValueHandlers.handleReturnValue( returnValue, getReturnValueType(returnValue), mavContainer, webRequest); } catch (Exception ex) { if (logger.isTraceEnabled()) { logger.trace(formatErrorForReturnValue(returnValue), ex); } throw ex; } }

org.springframework.web.method.support.InvocableHandlerMethod#invokeForRequest

public Object invokeForRequest(NativeWebRequest request, @Nullable ModelAndViewContainer mavContainer, Object... providedArgs) throws Exception { //获取方法的参数集合 Object[] args = getMethodArgumentValues(request, mavContainer, providedArgs); if (logger.isTraceEnabled()) { logger.trace("Arguments: " + Arrays.toString(args)); } return doInvoke(args); }

org.springframework.web.method.support.InvocableHandlerMethod#getMethodArgumentValues

protected Object[] getMethodArgumentValues(NativeWebRequest request, @Nullable ModelAndViewContainer mavContainer, Object... providedArgs) throws Exception { //获取方法所有参数,参数名,参数索引,参数类型,注解等属性 MethodParameter[] parameters = getMethodParameters(); if (ObjectUtils.isEmpty(parameters)) { return EMPTY_ARGS; } //创建一个一样长度的数组用来绑定参数 Object[] args = new Object[parameters.length]; for (int i = 0; i < parameters.length; i++) { MethodParameter parameter = parameters[i]; parameter.initParameterNameDiscovery(this.parameterNameDiscoverer); /** * 调用方提供的参数,不是请求时带来的参数 * providedArgs这个东东是空没有值的 */ args[i] = findProvidedArgument(parameter, providedArgs); if (args[i] != null) { continue; } //将参数解析器是否支持 if (!this.resolvers.supportsParameter(parameter)) { throw new IllegalStateException(formatArgumentError(parameter, "No suitable resolver")); } try { //解析参数并绑定 args[i] = this.resolvers.resolveArgument(parameter, mavContainer, request, this.dataBinderFactory); } catch (Exception ex) { // Leave stack trace for later, exception may actually be resolved and handled... if (logger.isDebugEnabled()) { String exMsg = ex.getMessage(); if (exMsg != null && !exMsg.contains(parameter.getExecutable().toGenericString())) { logger.debug(formatArgumentError(parameter, exMsg)); } } throw ex; } } return args; }

org.springframework.web.method.support.HandlerMethodArgumentResolverComposite#resolveArgument

public Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer, NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception { //获取参数解析器 HandlerMethodArgumentResolver resolver = getArgumentResolver(parameter); if (resolver == null) { throw new IllegalArgumentException("Unsupported parameter type [" + parameter.getParameterType().getName() + "]. supportsParameter should be called first."); } //解析参数 return resolver.resolveArgument(parameter, mavContainer, webRequest, binderFactory); }

org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver#resolveArgument

public Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer, NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception { //获取参数解析器 HandlerMethodArgumentResolver resolver = getArgumentResolver(parameter); if (resolver == null) { throw new IllegalArgumentException("Unsupported parameter type [" + parameter.getParameterType().getName() + "]. supportsParameter should be called first."); } //解析参数 return resolver.resolveArgument(parameter, mavContainer, webRequest, binderFactory); }

org.springframework.web.method.annotation.RequestParamMethodArgumentResolver#resolveName

protected Object resolveName(String name, MethodParameter parameter, NativeWebRequest request) throws Exception { HttpServletRequest servletRequest = request.getNativeRequest(HttpServletRequest.class); if (servletRequest != null) { Object mpArg = MultipartResolutionDelegate.resolveMultipartArgument(name, parameter, servletRequest); if (mpArg != MultipartResolutionDelegate.UNRESOLVABLE) { return mpArg; } } Object arg = null; MultipartRequest multipartRequest = request.getNativeRequest(MultipartRequest.class); if (multipartRequest != null) { List<MultipartFile> files = multipartRequest.getFiles(name); if (!files.isEmpty()) { arg = (files.size() == 1 ? files.get(0) : files); } } if (arg == null) { //从请求去拿出参数 String[] paramValues = request.getParameterValues(name); if (paramValues != null) { arg = (paramValues.length == 1 ? paramValues[0] : paramValues); } } return arg; }

org.springframework.web.method.support.InvocableHandlerMethod#doInvoke方法

@Nullable protected Object doInvoke(Object... args) throws Exception { //获取方法并授权method.setAccessible(true); ReflectionUtils.makeAccessible(getBridgedMethod()); try { //反射调用 return getBridgedMethod().invoke(getBean(), args); }