1.SpringMVC 下获取 web 资源的功能实现

WebMvcAutoConfiguration （ mvc 自动配置类）中的添加资源处理器代码如下 :

 public void addResourceHandlers(ResourceHandlerRegistry registry) {

          // 如果静态资源已经自定义，就失效了

            if (!this.resourceProperties.isAddMappings()) {

                logger.debug("Default resource handling disabled");

            } else {

                Duration cachePeriod = this.resourceProperties.getCache().getPeriod();

                CacheControl cacheControl = this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl();

           //webjars 比较热门的有 jquery,npm,Bootstrap, 以 maven 的方式去 import

                if (!registry.hasMappingForPattern("/webjars/**"))

           this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{"/webjars/**"}).addResourceLocations(new String[]{"classpath:/META-INF/resources/webjars/"}).setCachePeriod(this.getSeconds(cachePeriod)).setCacheControl(cacheControl));

                }

           // 方法二：获得资源路径

                String staticPathPattern = this.mvcProperties.getStaticPathPattern();

                if (!registry.hasMappingForPattern(staticPathPattern))

        this.customizeResourceHandlerRegistration(registry.addResourceHandler(new String[]{staticPathPattern}).addResourceLocations(getResourceLocations(this.resourceProperties.getStaticLocations())).setCachePeriod(this.getSeconds(cachePeriod)).setCacheControl(cacheControl));

                }

            }

        }

SpringMVC 下定制首页

WebMvcAutoConfiguration （ mvc 自动配置类）中的获得首页代码如下 :

@Bean

        public WelcomePageHandlerMapping welcomePageHandlerMapping(ApplicationContext applicationContext) {

        //

            return new WelcomePageHandlerMapping(new TemplateAvailabilityProviders(applicationContext), applicationContext, this.getWelcomePage(), this.mvcProperties.getStaticPathPattern());

        }

        static String[] getResourceLocations(String[] staticLocations) {

            String[] locations = new String[staticLocations.length + WebMvcAutoConfiguration.SERVLET_LOCATIONS.length];

            System.arraycopy(staticLocations, 0, locations, 0, staticLocations.length);

            System.arraycopy(WebMvcAutoConfiguration.SERVLET_LOCATIONS, 0, locations, staticLocations.length, WebMvcAutoConfiguration.SERVLET_LOCATIONS.length);

            return locations;

        }

        private Optional getWelcomePage() {

            String[] locations = getResourceLocations(this.resourceProperties.getStaticLocations());

            return Arrays.stream(locations).map(this::getIndexHtml).filter(this::isReadable).findFirst();

        }

       //index 是默认的首页文件名

        private Resource getIndexHtml(String location) {

            return this.resourceLoader.getResource(location + "index.html");

        }

注：springboot 中，在 template 目录下的所有页面只能通过 Controller 来跳转！给个例子

import org.springframework.stereotype.Controller;

import org.springframework.web.bind.annotation.GetMapping;

@Controller

public class CanController {

    @GetMapping("/first")

    public String say(){

        return "begin";

begin.html 中的内容：

    

    

    

    

    

    

    

        

•              CAN 报文解析