Map,model里面的数据都会放在request的请求与 request.setAttribute
@Controller
public class HelloController {
@RequestMapping("/hh")
public String hello()
{
return "aaa";
}
@GetMapping("/params")
public String testParam(Map<String,Object> map,
Model model,
HttpServletResponse response,
HttpServletRequest request){
map.put("hello","world");
model.addAttribute("world","helloworld");
request.setAttribute("message","message");
return "forward:/success";
}
@ResponseBody
@GetMapping("/success")
public Map sucess(HttpServletRequest request)
{
Map<String,Object> map = new HashMap<>();
Object hello = request.getAttribute("hello");
Object world = request.getAttribute("world");
Object message = request.getAttribute("message");
map.put("hello",hello);
map.put("world",world);
map.put("message",message);
return map;
}
}
访问结果如下
http://localhost:8080/params
{“world”:“helloworld”,“hello”:“world”,“message”:“message”}
直接从如下代码开始调试
protected HandlerAdapter getHandlerAdapter(Object handler) throws ServletException {
if (this.handlerAdapters != null) {
Iterator var2 = this.handlerAdapters.iterator();
while(var2.hasNext()) {
HandlerAdapter adapter = (HandlerAdapter)var2.next();
if (adapter.supports(handler)) {
return adapter;
}
}
}
throw new ServletException("No adapter for handler [" + handler + "]: The DispatcherServlet configuration needs to include a HandlerAdapter that supports this handler");
}
mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
mav = this.invokeHandlerMethod(request, response, handlerMethod);
invocableMethod.invokeAndHandle(webRequest, mavContainer, new Object[0]);
Object returnValue = this.invokeForRequest(webRequest, mavContainer, providedArgs);
if (!this.resolvers.supportsParameter(parameter))
return this.getArgumentResolver(parameter) != null;
if (resolver.supportsParameter(parameter)) {
this.argumentResolvers 到这里会发现有27个解析器
传入的第一个map 通过MapMethodProcess@6835
第二个model 通过ModelMethodProcess@6724
获取到解析器后 通过解析器 解析参数
@Nullable
public Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer, NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception {
HandlerMethodArgumentResolver resolver = this.getArgumentResolver(parameter);
if (resolver == null) {
throw new IllegalArgumentException("Unsupported parameter type [" + parameter.getParameterType().getName() + "]. supportsParameter should be called first.");
} else {
return resolver.resolveArgument(parameter, mavContainer, webRequest, binderFactory);
}
}
public Object resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer, NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory) throws Exception {
Assert.state(mavContainer != null, "ModelAndViewContainer is required for model exposure");
return mavContainer.getModel();
}
返回的是ModelAndViewContainer
HttpServletResponse response第三个参数 用的是ServletResponseMethodArgumentResolver解析器
HttpRequest 最后一个参数用的是ServletRequestMethodARgumentResolver解析器
获取完这四个参数
0 = {BindingAwareModelMap@6902} size = 0
1 = {BindingAwareModelMap@6902} size = 0
2 = {ResponseFacade@5833}
3 = {RequestFacade@5832}
会发现前两个相同 所以map和model本质处理是一样的
上述处理完之后
public void invokeAndHandle(ServletWebRequest webRequest, ModelAndViewContainer mavContainer, Object... providedArgs) throws Exception {
Object returnValue = this.invokeForRequest(webRequest, mavContainer, providedArgs);
this.setResponseStatus(webRequest);
if (returnValue == null) {
if (this.isRequestNotModified(webRequest) || this.getResponseStatus() != null || mavContainer.isRequestHandled()) {
this.disableContentCachingIfNecessary(webRequest);
mavContainer.setRequestHandled(true);
return;
}
} else if (StringUtils.hasText(this.getResponseStatusReason())) {
mavContainer.setRequestHandled(true);
return;
}
mavContainer.setRequestHandled(false);
Assert.state(this.returnValueHandlers != null, "No return value handlers");
try {
this.returnValueHandlers.handleReturnValue(returnValue, this.getReturnValueType(returnValue), mavContainer, webRequest);
处理返回结果 mavContainer包含了 这两个参数
} catch (Exception var6) {
if (logger.isTraceEnabled()) {
logger.trace(this.formatErrorForReturnValue(returnValue), var6);
}
throw var6;
}
}
进入
public void handleReturnValue(@Nullable Object returnValue, MethodParameter returnType, ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception {
HandlerMethodReturnValueHandler handler = this.selectHandler(returnValue, returnType);
if (handler == null) {
throw new IllegalArgumentException("Unknown return value type: " + returnType.getParameterType().getName());
} else {
handler.handleReturnValue(returnValue, returnType, mavContainer, webRequest);
进入
}
}
public void handleReturnValue(@Nullable Object returnValue, MethodParameter returnType, ModelAndViewContainer mavContainer, NativeWebRequest webRequest) throws Exception {
if (returnValue instanceof CharSequence) {
如果是返回值是字符串 获取该字符串 调试可得出 字符串是forward:/success
String viewName = returnValue.toString();
mavContainer.setViewName(viewName);
将该字符串放入mavContainer容器中
if (this.isRedirectViewName(viewName)) {
mavContainer.setRedirectModelScenario(true);
}
} else if (returnValue != null) {
throw new UnsupportedOperationException("Unexpected return type: " + returnType.getParameterType().getName() + " in method: " + returnType.getMethod());
}
}
介绍一下ModelAndViewContainer mavContainer 里面有一个 private final ModelMap defaultModel = new BindingAwareModelMap(); 既是一个Model 又是一个Map 继承的Map
上述执行完之后ModelAndView mavContainer携带了 数据和视图
var15 = this.getModelAndView(mavContainer, modelFactory, webRequest); 然后调用该方法
@Nullable
private ModelAndView getModelAndView(ModelAndViewContainer mavContainer, ModelFactory modelFactory, NativeWebRequest webRequest) throws Exception {
modelFactory.updateModel(webRequest, mavContainer);
进入
if (mavContainer.isRequestHandled()) {
return null;
} else {
ModelMap model = mavContainer.getModel();
ModelAndView mav = new ModelAndView(mavContainer.getViewName(), model, mavContainer.getStatus());
if (!mavContainer.isViewReference()) {
mav.setView((View)mavContainer.getView());
}
if (model instanceof RedirectAttributes) {
Map<String, ?> flashAttributes = ((RedirectAttributes)model).getFlashAttributes();
HttpServletRequest request = (HttpServletRequest)webRequest.getNativeRequest(HttpServletRequest.class);
if (request != null) {
RequestContextUtils.getOutputFlashMap(request).putAll(flashAttributes);
}
}
return mav;
}
}
}
public void updateModel(NativeWebRequest request, ModelAndViewContainer container) throws Exception {
ModelMap defaultModel = container.getDefaultModel();
从容器中获取了这两个参数
"hello" -> "world"
"world" -> "helloworld"
if (container.getSessionStatus().isComplete()) {
this.sessionAttributesHandler.cleanupAttributes(request);
} else {
this.sessionAttributesHandler.storeAttributes(request, defaultModel);
}
if (!container.isRequestHandled() && container.getModel() == defaultModel) {
this.updateBindingResult(request, defaultModel);
更新绑定结果 进入
}
}
==================
private void updateBindingResult(NativeWebRequest request, ModelMap model) throws Exception {
List<String> keyNames = new ArrayList(model.keySet());
拿到所有的Key
Iterator var4 = keyNames.iterator();
while(var4.hasNext()) {
String name = (String)var4.next();
Object value = model.get(name);
if (value != null && this.isBindingCandidate(name, value)) {
如果需要绑定 就用 这里面没有绑定
String bindingResultKey = BindingResult.MODEL_KEY_PREFIX + name;
if (!model.containsAttribute(bindingResultKey)) {
WebDataBinder dataBinder = this.dataBinderFactory.createBinder(request, value, name);
model.put(bindingResultKey, dataBinder.getBindingResult());
}
}
}
}
处理完上述之后
@Nullable
private ModelAndView getModelAndView(ModelAndViewContainer mavContainer, ModelFactory modelFactory, NativeWebRequest webRequest) throws Exception {
modelFactory.updateModel(webRequest, mavContainer);
if (mavContainer.isRequestHandled()) {
return null;
} else {
ModelMap model = mavContainer.getModel();
重新封装了ModelAndView model保存着传入的数据
ModelAndView mav = new ModelAndView(mavContainer.getViewName(), model, mavContainer.getStatus());
if (!mavContainer.isViewReference()) {
mav.setView((View)mavContainer.getView());
}
判断携带的数据是不是重定向的数据，如果是的华放入请求上下文 ，这里不是
if (model instanceof RedirectAttributes) {
Map<String, ?> flashAttributes = ((RedirectAttributes)model).getFlashAttributes();
HttpServletRequest request = (HttpServletRequest)webRequest.getNativeRequest(HttpServletRequest.class);
if (request != null) {
RequestContextUtils.getOutputFlashMap(request).putAll(flashAttributes);
}
}
return mav;
}
}
}
上述执行完之后 返回到DoDispath
if (!mappedHandler.applyPreHandle(processedRequest, response)) {
return;
}
mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
该一行执行完了
if (asyncManager.isConcurrentHandlingStarted()) {
return;
}
this.applyDefaultViewName(processedRequest, mv);
mappedHandler.applyPostHandle(processedRequest, response, mv);
拦截器相关 暂时不看
} catch (Exception var20) {
dispatchException = var20;
} catch (Throwable var21) {
dispatchException = new NestedServletException("Handler dispatch failed", var21);
}
this.processDispatchResult(processedRequest, response, mappedHandler, mv, (Exception)dispatchException);这里进入 处理派生结果
```java
private void processDispatchResult(HttpServletRequest request, HttpServletResponse response, @Nullable HandlerExecutionChain mappedHandler, @Nullable ModelAndView mv, @Nullable 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 = this.processHandlerException(request, response, handler, exception);
errorView = mv != null;
}
}
if (mv != null && !mv.wasCleared()) {
this.render(mv, request, response);
渲染进入
if (errorView) {
WebUtils.clearErrorRequestAttributes(request);
}
} else if (this.logger.isTraceEnabled()) {
this.logger.trace("No view rendering, null ModelAndView returned.");
}
if (!WebAsyncUtils.getAsyncManager(request).isConcurrentHandlingStarted()) {
if (mappedHandler != null) {
mappedHandler.triggerAfterCompletion(request, response, (Exception)null);
}
}
}
protected void render(ModelAndView mv, HttpServletRequest request, HttpServletResponse response) throws Exception {
Locale locale = this.localeResolver != null ? this.localeResolver.resolveLocale(request) : request.getLocale();
response.setLocale(locale);
String viewName = mv.getViewName();
视图名：forward:/sucess
View view;
if (viewName != null) {
view = this.resolveViewName(viewName, mv.getModelInternal(), locale, request);
解析视图 进入
if (view == null) {
throw new ServletException("Could not resolve view with name '" + mv.getViewName() + "' in servlet with name '" + this.getServletName() + "'");
}
} else {
view = mv.getView();
if (view == null) {
throw new ServletException("ModelAndView [" + mv + "] neither contains a view name nor a View object in servlet with name '" + this.getServletName() + "'");
}
}
if (this.logger.isTraceEnabled()) {
this.logger.trace("Rendering view [" + view + "] ");
}
try {
if (mv.getStatus() != null) {
request.setAttribute(View.RESPONSE_STATUS_ATTRIBUTE, mv.getStatus());
response.setStatus(mv.getStatus().value());
}
view.render(mv.getModelInternal(), request, response);
} catch (Exception var8) {
if (this.logger.isDebugEnabled()) {
this.logger.debug("Error rendering view [" + view + "]", var8);
}
throw var8;
}
}
@Nullable
protected View resolveViewName(String viewName, @Nullable Map<String, Object> model, Locale locale, HttpServletRequest request) throws Exception {
参数model存放的是 最开始model和map的两个参数
if (this.viewResolvers != null) {
Iterator var5 = this.viewResolvers.iterator();
while(var5.hasNext()) {
ViewResolver viewResolver = (ViewResolver)var5.next();
View view = viewResolver.resolveViewName(viewName, locale);
进入
if (view != null) {
return view;
}
}
}
return null;
}
@Nullable
public View resolveViewName(String viewName, Locale locale) throws Exception {
RequestAttributes attrs = RequestContextHolder.getRequestAttributes();
Assert.state(attrs instanceof ServletRequestAttributes, "No current ServletRequestAttributes");
List<MediaType> requestedMediaTypes = this.getMediaTypes(((ServletRequestAttributes)attrs).getRequest());
if (requestedMediaTypes != null) {
List<View> candidateViews = this.getCandidateViews(viewName, locale, requestedMediaTypes);
View bestView = this.getBestView(candidateViews, requestedMediaTypes, attrs);
if (bestView != null) {
return bestView;
拿到视图 返回
}
}
String mediaTypeInfo = this.logger.isDebugEnabled() && requestedMediaTypes != null ? " given " + requestedMediaTypes.toString() : "";
if (this.useNotAcceptableStatusCode) {
if (this.logger.isDebugEnabled()) {
this.logger.debug("Using 406 NOT_ACCEPTABLE" + mediaTypeInfo);
}
return NOT_ACCEPTABLE_VIEW;
} else {
this.logger.debug("View remains unresolved" + mediaTypeInfo);
return null;
}
}
拿到视图继续返回
protected void render(ModelAndView mv, HttpServletRequest request, HttpServletResponse response) throws Exception {
Locale locale = this.localeResolver != null ? this.localeResolver.resolveLocale(request) : request.getLocale();
response.setLocale(locale);
String viewName = mv.getViewName();
View view;
if (viewName != null) {
view = this.resolveViewName(viewName, mv.getModelInternal(), locale, request);
拿到视图
if (view == null) {
throw new ServletException("Could not resolve view with name '" + mv.getViewName() + "' in servlet with name '" + this.getServletName() + "'");
}
} else {
view = mv.getView();
if (view == null) {
throw new ServletException("ModelAndView [" + mv + "] neither contains a view name nor a View object in servlet with name '" + this.getServletName() + "'");
}
}
if (this.logger.isTraceEnabled()) {
this.logger.trace("Rendering view [" + view + "] ");
}
try {
if (mv.getStatus() != null) {
request.setAttribute(View.RESPONSE_STATUS_ATTRIBUTE, mv.getStatus());
response.setStatus(mv.getStatus().value());
}
view.render(mv.getModelInternal(), request, response);
从这里进入
} catch (Exception var8) {
if (this.logger.isDebugEnabled()) {
this.logger.debug("Error rendering view [" + view + "]", var8);
}
throw var8;
}
}
public void render(@Nullable Map<String, ?> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
if (this.logger.isDebugEnabled()) {
this.logger.debug("View " + this.formatViewName() + ", model " + (model != null ? model : Collections.emptyMap()) + (this.staticAttributes.isEmpty() ? "" : ", static attributes " + this.staticAttributes));
}
Map<String, Object> mergedModel = this.createMergedOutputModel(model, request, response);
进入
this.prepareResponse(request, response);
this.renderMergedOutputModel(mergedModel, this.getRequestToExpose(request), response);
}
protected Map<String, Object> createMergedOutputModel(@Nullable Map<String, ?> model, HttpServletRequest request, HttpServletResponse response) {
Map<String, Object> pathVars = this.exposePathVariables ? (Map)request.getAttribute(View.PATH_VARIABLES) : null;
int size = this.staticAttributes.size();
size += model != null ? model.size() : 0;
size += pathVars != null ? pathVars.size() : 0;
Map<String, Object> mergedModel = CollectionUtils.newLinkedHashMap(size);
mergedModel.putAll(this.staticAttributes);
if (pathVars != null) {
mergedModel.putAll(pathVars);
}
if (model != null) {
mergedModel.putAll(model);
将model里面的数据全部放在mergeModel，mergeModel是一个HashMap
}
if (this.requestContextAttribute != null) {
mergedModel.put(this.requestContextAttribute, this.createRequestContext(request, response, mergedModel));
}
return mergedModel;
}
放入之后返回
public void render(@Nullable Map<String, ?> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
if (this.logger.isDebugEnabled()) {
this.logger.debug("View " + this.formatViewName() + ", model " + (model != null ? model : Collections.emptyMap()) + (this.staticAttributes.isEmpty() ? "" : ", static attributes " + this.staticAttributes));
}
Map<String, Object> mergedModel = this.createMergedOutputModel(model, request, response);
上一行执行完了代码
this.prepareResponse(request, response);
this.renderMergedOutputModel(mergedModel, this.getRequestToExpose(request), response);
渲染合并输出的模型数据 进入
}
protected void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
this.exposeModelAsRequestAttributes(model, request);
把暴露模型作为请求域属性 进入
this.exposeHelpers(request);
String dispatcherPath = this.prepareForRendering(request, response);
RequestDispatcher rd = this.getRequestDispatcher(request, dispatcherPath);
if (rd == null) {
throw new ServletException("Could not get RequestDispatcher for [" + this.getUrl() + "]: Check that the corresponding file exists within your web application archive!");
} else {
if (this.useInclude(request, response)) {
response.setContentType(this.getContentType());
if (this.logger.isDebugEnabled()) {
this.logger.debug("Including [" + this.getUrl() + "]");
}
rd.include(request, response);
} else {
if (this.logger.isDebugEnabled()) {
this.logger.debug("Forwarding to [" + this.getUrl() + "]");
}
rd.forward(request, response);
}
}
}
protected void exposeModelAsRequestAttributes(Map<String, Object> model, HttpServletRequest request) throws Exception {
model.forEach((name, value) -> {
if (value != null) {
request.setAttribute(name, value);
} else {
request.removeAttribute(name);
}
});
}
到此结束
