請(qǐng)求映射原理請(qǐng)求過(guò)來(lái)首先進(jìn)入
javax.servlet.http.HttpServlet#doGet()->
org.springframework.web.servlet.FrameworkServlet#doGet()->
org.springframework.web.servlet.FrameworkServlet#processRequest()->
org.springframework.web.servlet.DispatcherServlet#doService()->
org.springframework.web.servlet.DispatcherServlet#doDispatch()->
protected void doDispatch(HttpServletRequest request, HttpServletResponse response)
throws Exception {
...
//找到當(dāng)前請(qǐng)求使用哪個(gè)handler(controller的方法)處理
mappedHandler = getHandler(processedRequest);
if (mappedHandler == null) {
noHandlerFound(processedRequest, response);
return;
}
//為當(dāng)前handler找到合適的handler適配器
HandlerAdapter ha = getHandlerAdapter(mappedHandler.getHandler());
...
// 真正的調(diào)用
mv = ha.handle(processedRequest, response, mappedHandler.getHandler());
...
}
RequestMappingHandlerMapping:保存了所有@RequestMapping 和handler的映射規(guī)則。
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter#handleInternal()->
protected ModelAndView handleInternal(HttpServletRequest request,
HttpServletResponse response, HandlerMethod handlerMethod) throws Exception {
...
mav = invokeHandlerMethod(request, response, handlerMethod);
...
}
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter#invokeHandlerMethod()->
protected ModelAndView invokeHandlerMethod(HttpServletRequest request,
HttpServletResponse response, HandlerMethod handlerMethod) throws Exception {
...
//傳參解析器
if (this.argumentResolvers != null) {
invocableMethod.setHandlerMethodArgumentResolvers(this.argumentResolvers);
}
//返參處理器
if (this.returnValueHandlers != null) {
invocableMethod.setHandlerMethodReturnValueHandlers(this.returnValueHandlers);
}
invocableMethod.invokeAndHandle(webRequest, mavContainer);
}
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod#invokeAndHandle()->
public void invokeAndHandle(ServletWebRequest webRequest, ModelAndViewContainer mavContainer,
Object... providedArgs) throws Exception {
Object returnValue = invokeForRequest(webRequest, mavContainer, providedArgs);
...
}
org.springframework.web.method.support.InvocableHandlerMethod#invokeForRequest()
public Object invokeForRequest(NativeWebRequest request, @Nullable ModelAndViewContainer mavContainer,
Object... providedArgs) throws Exception {
//準(zhǔn)備目標(biāo)方法的參數(shù)值
Object[] args = getMethodArgumentValues(request, mavContainer, providedArgs);
...
return doInvoke(args);
}
參數(shù)解析器HandlerMethodArgumentResolver 是為了確定將要執(zhí)行的目標(biāo)方法的每一個(gè)參數(shù)的值是什么。SpringMVC目標(biāo)方法能寫(xiě)多少種參數(shù)類(lèi)型,取決于參數(shù)解析器。
返回值處理器HandlerMethodReturnValueHandler 是為了封裝返回?cái)?shù)據(jù)的參數(shù)類(lèi)型。
封裝handler各參數(shù)值的主要邏輯
org.springframework.web.method.support.InvocableHandlerMethod#getMethodArgumentValues()
protected Object[] getMethodArgumentValues(NativeWebRequest request, @Nullable ModelAndViewContainer mavContainer,
Object... providedArgs) throws Exception {
MethodParameter[] parameters = getMethodParameters();
if (ObjectUtils.isEmpty(parameters)) {
return EMPTY_ARGS;
}
Object[] args = new Object[parameters.length];
for (int i = 0; i< parameters.length; i++) {
MethodParameter parameter = parameters[i];
parameter.initParameterNameDiscovery(this.parameterNameDiscoverer);
args[i] = findProvidedArgument(parameter, providedArgs);
if (args[i] != null) {
continue;
}
if (!this.resolvers.supportsParameter(parameter)) {
throw new IllegalStateException(formatArgumentError(parameter, "No suitable resolver"));
}
try {
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;
}
你是否還在尋找穩(wěn)定的海外服務(wù)器提供商?創(chuàng)新互聯(lián)www.cdcxhl.cn海外機(jī)房具備T級(jí)流量清洗系統(tǒng)配攻擊溯源,準(zhǔn)確流量調(diào)度確保服務(wù)器高可用性,企業(yè)級(jí)服務(wù)器適合批量采購(gòu),新人活動(dòng)首月15元起,快前往官網(wǎng)查看詳情吧
網(wǎng)站題目:springmvc請(qǐng)求映射原理-創(chuàng)新互聯(lián)
網(wǎng)站鏈接:http://vcdvsql.cn/article8/ceohip.html
成都網(wǎng)站建設(shè)公司_創(chuàng)新互聯(lián),為您提供ChatGPT、面包屑導(dǎo)航、App設(shè)計(jì)、服務(wù)器托管、建站公司、營(yíng)銷(xiāo)型網(wǎng)站建設(shè)
聲明:本網(wǎng)站發(fā)布的內(nèi)容(圖片、視頻和文字)以用戶投稿、用戶轉(zhuǎn)載內(nèi)容為主,如果涉及侵權(quán)請(qǐng)盡快告知,我們將會(huì)在第一時(shí)間刪除。文章觀點(diǎn)不代表本網(wǎng)站立場(chǎng),如需處理請(qǐng)聯(lián)系客服。電話:028-86922220;郵箱:631063699@qq.com。內(nèi)容未經(jīng)允許不得轉(zhuǎn)載,或轉(zhuǎn)載時(shí)需注明來(lái)源: 創(chuàng)新互聯(lián)
猜你還喜歡下面的內(nèi)容