SpringBoot中对SpringMVC的自动配置详解

public View resolveViewName(String viewName, Locale locale) throws Exception {
        RequestAttributes attrs = RequestContextHolder.getRequestAttributes();
        Assert.state(attrs instanceof ServletRequestAttributes, "No current ServletRequestAttributes");
        List<MediaType> requestedMediaTypes = getMediaTypes(((ServletRequestAttributes) attrs).getRequest());
        if (requestedMediaTypes != null) {
            List<View> candidateViews = getCandidateViews(viewName, locale, requestedMediaTypes);　　　　　　　　　　//获取所有View
            View bestView = getBestView(candidateViews, requestedMediaTypes, attrs);　　　　　　　　　　　　　　　　　　//获得正确的View
            if (bestView != null) {
                return bestView;
            }
        }

@Override
        public void addFormatters(FormatterRegistry registry) {
            for (Converter<?, ?> converter : getBeansOfType(Converter.class)) {
                registry.addConverter(converter);
            }
            for (GenericConverter converter : getBeansOfType(GenericConverter.class)) {
                registry.addConverter(converter);
            }
            for (Formatter<?> formatter : getBeansOfType(Formatter.class)) {
                registry.addFormatter(formatter);
            }
        }

@Override
        protected ConfigurableWebBindingInitializer getConfigurableWebBindingInitializer() {
            try {
                return this.beanFactory.getBean(ConfigurableWebBindingInitializer.class);
            }
            catch (NoSuchBeanDefinitionException ex) {
                return super.getConfigurableWebBindingInitializer();
            }
        }

<mvc:interceptors>
    <mvc:interceptor>
        <mvc:mapping path="/hello"/>
        <bean></bean>
    </mvc:interceptor>
</mvc:interceptors>

//使用WebMvcConfigurerAdapter可以来扩展SpringMVC的功能
@Configuration
public class MyMvcConfig extends WebMvcConfigurationSupport{
　　@Autowired
　　private UserTokenInterceptor userTokenInterceptor;
　　@Override
　　public void addInterceptors(InterceptorRegistry registry) {
　　　　// 多个拦截器组成一个拦截器链
　　　　// addPathPatterns 用于添加拦截规则
　　　　// excludePathPatterns 用户排除拦截
　　　　registry.addInterceptor(userTokenInterceptor).addPathPatterns("/**")
　　　　　　.excludePathPatterns("/account/login","/account/register");
　　　　super.addInterceptors(registry);
　　}

}

@Autowired(required = false)
    public void setConfigurers(List<WebMvcConfigurer> configurers) {
        if (!CollectionUtils.isEmpty(configurers)) {
            this.configurers.addWebMvcConfigurers(configurers);
        }
    }

//使用WebMvcConfigurerAdapter可以来扩展SpringMVC的功能
@EnableWebMvc
@Configuration
public class MyMvcConfig extends WebMvcConfigurerAdapter {
　　@Override
　　public void addViewControllers(ViewControllerRegistry registry) {
　　　　// super.addViewControllers(registry);
　　　　//浏览器发送 /hello 请求来到 success
　　　　registry.addViewController("/hello").setViewName("success");
　　}
}

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.TYPE)
@Documented
@Import(DelegatingWebMvcConfiguration.class)
public @interface EnableWebMvc {
}

@Configuration
public class DelegatingWebMvcConfiguration extends WebMvcConfigurationSupport {
}

@Configuration
@ConditionalOnWebApplication(type = Type.SERVLET)
@ConditionalOnClass({ Servlet.class, DispatcherServlet.class, WebMvcConfigurer.class })
//容器中没有这个组件的时候，这个自动配置类才生效
@ConditionalOnMissingBean(WebMvcConfigurationSupport.class)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10)
@AutoConfigureAfter({ DispatcherServletAutoConfiguration.class, TaskExecutionAutoConfiguration.class,
        ValidationAutoConfiguration.class })
public class WebMvcAutoConfiguration {