public void initApplicationContext() throws ApplicationContextException {
        super.initApplicationContext();
        detectHandlers();
    }
    /**
　　  * 建立当前ApplicationContext中的所有controller和url的对应关系
　　　 */
    protected void detectHandlers() throws BeansException {
        if (logger.isDebugEnabled()) {
            logger.debug("Looking for URL mappings in application context: " + getApplicationContext());
        }
　　　　 // 获取ApplicationContext容器中所有bean的Name
        String[] beanNames = (this.detectHandlersInAncestorContexts ?
                BeanFactoryUtils.beanNamesForTypeIncludingAncestors(getApplicationContext(), Object.class) :
                getApplicationContext().getBeanNamesForType(Object.class));

        // 遍历beanNames,并找到这些bean对应的url
        for (String beanName : beanNames) {
　　　　　　 // 找bean上的所有url(controller上的url+方法上的url),该方法由对应的子类实现
            String[] urls = determineUrlsForHandler(beanName);
            if (!ObjectUtils.isEmpty(urls)) {
                // 保存urls和beanName的对应关系,put it to Map<urls,beanName>,该方法在父类AbstractUrlHandlerMapping中实现
                registerHandler(urls, beanName);
            }
            else {
                if (logger.isDebugEnabled()) {
                    logger.debug("Rejected bean name '" + beanName + "': no URL paths identified");
                }
            }
        }
    }
    /** 获取controller中所有方法的url,由子类实现,典型的模板模式 **/
　　protected abstract String[] determineUrlsForHandler(String beanName);

　/**
　　 * 获取controller中所有的url
     */
　　protected String[] determineUrlsForHandler(String beanName) {
       // 获取ApplicationContext容器 
　　　　ApplicationContext context = getApplicationContext();
        //从容器中获取controller
　　　　 Class<?> handlerType = context.getType(beanName);
　　　　 // 获取controller上的@RequestMapping注解
        RequestMapping mapping = context.findAnnotationOnBean(beanName, RequestMapping.class);
        if (mapping != null) { // controller上有注解
            this.cachedMappings.put(handlerType, mapping);
　　　　　　  // 返回结果集
            Set<String> urls = new LinkedHashSet<String>();
　　　　　　  // controller的映射url
            String[] typeLevelPatterns = mapping.value();
            if (typeLevelPatterns.length > 0) { // url>0
                // 获取controller中所有方法及方法的映射url
                String[] methodLevelPatterns = determineUrlsForHandlerMethods(handlerType, true);
                for (String typeLevelPattern : typeLevelPatterns) {
                    if (!typeLevelPattern.startsWith("/")) {
                        typeLevelPattern = "/" + typeLevelPattern;
                    }
                    boolean hasEmptyMethodLevelMappings = false;
                    for (String methodLevelPattern : methodLevelPatterns) {
                        if (methodLevelPattern == null) {
                            hasEmptyMethodLevelMappings = true;
                        }
                        else {
　　　　　　　　　　　　　　　　// controller的映射url+方法映射的url
                            String combinedPattern = getPathMatcher().combine(typeLevelPattern, methodLevelPattern);
　　　　　　　　　　　　　　　　// 保存到set集合中
　　　　　　　　　　　　　　　　 addUrlsForPath(urls, combinedPattern);
                        }
                    }
                    if (hasEmptyMethodLevelMappings ||
                            org.springframework.web.servlet.mvc.Controller.class.isAssignableFrom(handlerType)) {
                        addUrlsForPath(urls, typeLevelPattern);
                    }
                }
　　　　　　　　　// 以数组形式返回controller上的所有url
                return StringUtils.toStringArray(urls);
            }
            else {
                // controller上的@RequestMapping映射url为空串,直接找方法的映射url
                return determineUrlsForHandlerMethods(handlerType, false);
            }
        } // controller上没@RequestMapping注解
        else if (AnnotationUtils.findAnnotation(handlerType, Controller.class) != null) {
            // 获取controller中方法上的映射url
            return determineUrlsForHandlerMethods(handlerType, false);
        }
        else {
            return null;
        }
    }

private Object[] resolveHandlerArguments(Method handlerMethod, Object handler,
            NativeWebRequest webRequest, ExtendedModelMap implicitModel) throws Exception {
　　　　 // 1.获取方法参数类型的数组
        Class[] paramTypes = handlerMethod.getParameterTypes();
　　　　// 声明数组,存参数的值
        Object[] args = new Object[paramTypes.length];
　　　　//2.遍历参数数组,获取每个参数的值
        for (int i = 0; i < args.length; i++) {
            MethodParameter methodParam = new MethodParameter(handlerMethod, i);
            methodParam.initParameterNameDiscovery(this.parameterNameDiscoverer);
            GenericTypeResolver.resolveParameterType(methodParam, handler.getClass());
            String paramName = null;
            String headerName = null;
            boolean requestBodyFound = false;
            String cookieName = null;
            String pathVarName = null;
            String attrName = null;
            boolean required = false;
            String defaultValue = null;
            boolean validate = false;
            int annotationsFound = 0;
            Annotation[] paramAnns = methodParam.getParameterAnnotations();
　　　　　　 // 处理参数上的注解
            for (Annotation paramAnn : paramAnns) {
                if (RequestParam.class.isInstance(paramAnn)) {
                    RequestParam requestParam = (RequestParam) paramAnn;
                    paramName = requestParam.value();
                    required = requestParam.required();
                    defaultValue = parseDefaultValueAttribute(requestParam.defaultValue());
                    annotationsFound++;
                }
                else if (RequestHeader.class.isInstance(paramAnn)) {
                    RequestHeader requestHeader = (RequestHeader) paramAnn;
                    headerName = requestHeader.value();
                    required = requestHeader.required();
                    defaultValue = parseDefaultValueAttribute(requestHeader.defaultValue());
                    annotationsFound++;
                }
                else if (RequestBody.class.isInstance(paramAnn)) {
                    requestBodyFound = true;
                    annotationsFound++;
                }
                else if (CookieValue.class.isInstance(paramAnn)) {
                    CookieValue cookieValue = (CookieValue) paramAnn;
                    cookieName = cookieValue.value();
                    required = cookieValue.required();
                    defaultValue = parseDefaultValueAttribute(cookieValue.defaultValue());
                    annotationsFound++;
                }
                else if (PathVariable.class.isInstance(paramAnn)) {
                    PathVariable pathVar = (PathVariable) paramAnn;
                    pathVarName = pathVar.value();
                    annotationsFound++;
                }
                else if (ModelAttribute.class.isInstance(paramAnn)) {
                    ModelAttribute attr = (ModelAttribute) paramAnn;
                    attrName = attr.value();
                    annotationsFound++;
                }
                else if (Value.class.isInstance(paramAnn)) {
                    defaultValue = ((Value) paramAnn).value();
                }
                else if ("Valid".equals(paramAnn.annotationType().getSimpleName())) {
                    validate = true;
                }
            }
　　
            if (annotationsFound > 1) {
                throw new IllegalStateException("Handler parameter annotations are exclusive choices - " +
                        "do not specify more than one such annotation on the same parameter: " + handlerMethod);
            }

            if (annotationsFound == 0) {// 如果没有注解
                Object argValue = resolveCommonArgument(methodParam, webRequest);
                if (argValue != WebArgumentResolver.UNRESOLVED) {
                    args[i] = argValue;
                }
                else if (defaultValue != null) {
                    args[i] = resolveDefaultValue(defaultValue);
                }
                else {
                    Class paramType = methodParam.getParameterType();
　　　　　　　　　　  // 将方法声明中的Map和Model参数,放到request中,用于将数据放到request中带回页面
                    if (Model.class.isAssignableFrom(paramType) || Map.class.isAssignableFrom(paramType)) {
                        args[i] = implicitModel;
                    }
                    else if (SessionStatus.class.isAssignableFrom(paramType)) {
                        args[i] = this.sessionStatus;
                    }
                    else if (HttpEntity.class.isAssignableFrom(paramType)) {
                        args[i] = resolveHttpEntityRequest(methodParam, webRequest);
                    }
                    else if (Errors.class.isAssignableFrom(paramType)) {
                        throw new IllegalStateException("Errors/BindingResult argument declared " +
                                "without preceding model attribute. Check your handler method signature!");
                    }
                    else if (BeanUtils.isSimpleProperty(paramType)) {
                        paramName = "";
                    }
                    else {
                        attrName = "";
                    }
                }
            }
　　　　　　　// 从request中取值,并进行赋值操作
            if (paramName != null) {
　　　　　　　　　// 根据paramName从request中取值,如果没有通过RequestParam注解指定paramName,则使用asm读取class文件来获取paramName
                args[i] = resolveRequestParam(paramName, required, defaultValue, methodParam, webRequest, handler);
            }
            else if (headerName != null) {
                args[i] = resolveRequestHeader(headerName, required, defaultValue, methodParam, webRequest, handler);
            }
            else if (requestBodyFound) {
                args[i] = resolveRequestBody(methodParam, webRequest, handler);
            }
            else if (cookieName != null) {
                args[i] = resolveCookieValue(cookieName, required, defaultValue, methodParam, webRequest, handler);
            }
            else if (pathVarName != null) {
                args[i] = resolvePathVariable(pathVarName, methodParam, webRequest, handler);
            }
            else if (attrName != null) {
                WebDataBinder binder =
                        resolveModelAttribute(attrName, methodParam, implicitModel, webRequest, handler);
                boolean assignBindingResult = (args.length > i + 1 && Errors.class.isAssignableFrom(paramTypes[i + 1]));
                if (binder.getTarget() != null) {
                    doBind(binder, webRequest, validate, !assignBindingResult);
                }
                args[i] = binder.getTarget();
                if (assignBindingResult) {
                    args[i + 1] = binder.getBindingResult();
                    i++;
                }
                implicitModel.putAll(binder.getBindingResult().getModel());
            }
        }
　　　　 // 返回参数值数组
        return args;
    }