SpringMVC源码解析

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

org.springframework.web.servlet.HandlerMapping=
　　　　org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping,//例如@Component("/index")
    　 org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping,//例如：@RequestMapping("/index")
    　 org.springframework.web.servlet.function.support.RouterFunctionMappingprivate void initHandlerMappings(ApplicationContext context)this.handlerMappings = null;

if (this.detectAllHandlerMappings) {
            // Find all HandlerMappings in the ApplicationContext, including ancestor contexts.
            // 从spring容器singletonObjects的list集合中拿出来所有的HandlerMapping
            Map<String, HandlerMapping> matchingBeans =
                    BeanFactoryUtils.beansOfTypeIncludingAncestors(context, HandlerMapping.class, true, false);
            if (!matchingBeans.isEmpty()) {
                this.handlerMappings = new ArrayList<>(matchingBeans.values());
                // We keep HandlerMappings in sorted order.
                AnnotationAwareOrderComparator.sort(this.handlerMappings);
            }
        }
        else {//默认不走这个方法，因为this.detectAllhandlerMappings为true
            try {
                HandlerMapping hm = context.getBean(HANDLER_MAPPING_BEAN_NAME, HandlerMapping.class);
                this.handlerMappings = Collections.singletonList(hm);
            }
            catch (NoSuchBeanDefinitionException ex) {
                // Ignore, we‘ll add a default HandlerMapping later.
            }
        }

        // Ensure we have at least one HandlerMapping, by registering
        // a default HandlerMapping if no other mappings are found.
　　　　// 通过配置文件中的配置的信息得到handlerMapping
        if (this.handlerMappings == null) {
            this.handlerMappings = getDefaultStrategies(context, HandlerMapping.class);
            if (logger.isTraceEnabled()) {
                logger.trace("No HandlerMappings declared for servlet ‘" + getServletName() +
                        "‘: using default strategies from DispatcherServlet.properties");
            }
        }
    }

protected <T> List<T> getDefaultStrategies(ApplicationContext context, Class<T> strategyInterface) {
        String key = strategyInterface.getName();
        String value = defaultStrategies.getProperty(key);
        if (value != null) {
            String[] classNames = StringUtils.commaDelimitedListToStringArray(value);
            List<T> strategies = new ArrayList<>(classNames.length);
            for (String className : classNames) {
                try {
                    Class<?> clazz = ClassUtils.forName(className, DispatcherServlet.class.getClassLoader());
                    Object strategy = createDefaultStrategy(context, clazz);
                    strategies.add((T) strategy);
                }
                catch (ClassNotFoundException ex) {
                    throw new BeanInitializationException(
                            "Could not find DispatcherServlet‘s default strategy class [" + className +
                            "] for interface [" + key + "]", ex);
                }
                catch (LinkageError err) {
                    throw new BeanInitializationException(
                            "Unresolvable class definition for DispatcherServlet‘s default strategy class [" +
                            className + "] for interface [" + key + "]", err);
                }
            }
            return strategies;
        }
        else {
            return new LinkedList<>();
        }
    }

private void initHandlerAdapters(ApplicationContext context) {
        this.handlerAdapters = null;

        if (this.detectAllHandlerAdapters) {
            // Find all HandlerAdapters in the ApplicationContext, including ancestor contexts.
            Map<String, HandlerAdapter> matchingBeans =
                    BeanFactoryUtils.beansOfTypeIncludingAncestors(context, HandlerAdapter.class, true, false);
            if (!matchingBeans.isEmpty()) {
                this.handlerAdapters = new ArrayList<>(matchingBeans.values());
                // We keep HandlerAdapters in sorted order.
                AnnotationAwareOrderComparator.sort(this.handlerAdapters);
            }
        }
        else {
            try {
                HandlerAdapter ha = context.getBean(HANDLER_ADAPTER_BEAN_NAME, HandlerAdapter.class);
                this.handlerAdapters = Collections.singletonList(ha);
            }
            catch (NoSuchBeanDefinitionException ex) {
                // Ignore, we‘ll add a default HandlerAdapter later.
            }
        }

        // Ensure we have at least some HandlerAdapters, by registering
        // default HandlerAdapters if no other adapters are found.
        if (this.handlerAdapters == null) {
            this.handlerAdapters = getDefaultStrategies(context, HandlerAdapter.class);
            if (logger.isTraceEnabled()) {
                logger.trace("No HandlerAdapters declared for servlet ‘" + getServletName() +
                        "‘: using default strategies from DispatcherServlet.properties");
            }
        }
    }

protected abstract void doService(HttpServletRequest request, HttpServletResponse response) throws Exception;

doDispatch(request, response);

processedRequest = checkMultipart(request)

mappedHandler = getHandler(processedRequest);