initHandlerMappings

 private void initHandlerMappings(ApplicationContext context) {
        this.handlerMappings = null;
        if (this.detectAllHandlerMappings) {
            Map<String, HandlerMapping> matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(context, HandlerMapping.class, true, false);
            if (!matchingBeans.isEmpty()) {
                this.handlerMappings = new ArrayList(matchingBeans.values());
                AnnotationAwareOrderComparator.sort(this.handlerMappings);
            }
        } else {
            try {
                HandlerMapping hm = (HandlerMapping)context.getBean("handlerMapping", HandlerMapping.class);
                this.handlerMappings = Collections.singletonList(hm);
            } catch (NoSuchBeanDefinitionException var3) {
                ;
            }
        }

        if (this.handlerMappings == null) {
            this.handlerMappings = this.getDefaultStrategies(context, HandlerMapping.class);
            if (this.logger.isTraceEnabled()) {
                this.logger.trace("No HandlerMappings declared for servlet "" + this.getServletName() + "": using default strategies from DispatcherServlet.properties");
            }
        }

    }

就是这么简单 从spring容器中获取HandlerMapping的bean
如果没有就创建一个默认的（默认文件就在mvc的jar包里 DispatcherServlet.properties）
完活
然而springboot中HandlerMapping这些是怎么注入的呢
默认的hanlerMapping实体有

• 0 = {PropertySourcedRequestMappingHandlerMapping@14317}
• 1 = {WebMvcEndpointHandlerMapping@14345}
• 2 = {ControllerEndpointHandlerMapping@14372}
• 3 = {RequestMappingHandlerMapping@14396}
• 4 = {BeanNameUrlHandlerMapping@15448}

initHandlerAdapters

与initHandlerMappings类似,从bean工程中获取HandlerAdapter的实现

private void initHandlerAdapters(ApplicationContext context) {
        this.handlerAdapters = null;
        if (this.detectAllHandlerAdapters) {
            Map<String, HandlerAdapter> matchingBeans = BeanFactoryUtils.beansOfTypeIncludingAncestors(context, HandlerAdapter.class, true, false);
            if (!matchingBeans.isEmpty()) {
                this.handlerAdapters = new ArrayList(matchingBeans.values());
                AnnotationAwareOrderComparator.sort(this.handlerAdapters);
            }
        } else {
            try {
                HandlerAdapter ha = (HandlerAdapter)context.getBean("handlerAdapter", HandlerAdapter.class);
                this.handlerAdapters = Collections.singletonList(ha);
            } catch (NoSuchBeanDefinitionException var3) {
                ;
            }
        }

        if (this.handlerAdapters == null) {
            this.handlerAdapters = this.getDefaultStrategies(context, HandlerAdapter.class);
            if (this.logger.isTraceEnabled()) {
                this.logger.trace("No HandlerAdapters declared for servlet "" + this.getServletName() + "": using default strategies from DispatcherServlet.properties");
            }
        }

    }

默认的hanlerMapping实体有

• 0 = {RequestMappingHandlerAdapter@6397} WebMvcAutoConfiguration
• 1 = {HttpRequestHandlerAdapter@6398} WebMvcConfigurationSupport
• 2 = {SimpleControllerHandlerAdapter@6399} WebMvcConfigurationSupport