SpringBoot之web開發概述SpringBoot對靜態資源(static-location)的對映規則模板引擎thymeleafthymeleaf基本概念引入thymeleaf依賴thymeleaf使用和語法SpringBoot對SpringMVC的web主要的自動配置如何修改SpringBoot的預設配置擴充套件MVC（不能標註@EnableWebMvc）全面接管SpringMVC（@EnableWebMvc）—不推薦使用概述SpringBoot開發：1.建立SpringBoot應用，選中需要的場景模組。2.SpringBoot已經預設將場景模組配置好，只需要在配置檔案中指定少量的配置(資料庫地址，使用者名稱，密碼)就可以執行起來。3.只需要編寫業務邏輯程式碼。需要掌握自動配置原理：這個場景中SpringBoot預設配置好了什麼，能不能修改，能修改哪些配置，能不能擴充套件。

XxxAutoConfiguration:幫我們給容器中自動配置元件XxxProperties：配置類，封裝配置檔案中的內容

@ConfigurationProperties(    prefix = "spring.resources",    ignoreUnknownFields = false)

 /*   * ResourceHandlerRegistry儲存用於透過Spring MVC服務靜態資源的資源處理程式的註冊  * 允許設定為在Web瀏覽器中高效載入而最佳化的快取頭  * 可以在Web應用的目錄下,類路徑等位置之外的位置提供資源  */ public void addResourceHandlers(ResourceHandlerRegistry registry) {             if (!this.resourceProperties.isAddMappings()) {                logger.debug("Default resource handling disabled");            } else {                Duration cachePeriod = this.resourceProperties.getCache().getPeriod();                CacheControl cacheControl = this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl();                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));                }                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));                }            }        }

classpath:/META-INF/resources/classpath:/resources/classpath:/static/classpath:/public//	# 當前專案的根路徑

 @Bean        public WelcomePageHandlerMapping welcomePageHandlerMapping(ApplicationContext applicationContext) {            return new WelcomePageHandlerMapping(new TemplateAvailabilityProviders(applicationContext), applicationContext, this.getWelcomePage(), this.mvcProperties.getStaticPathPattern());        }

配置歡迎頁的對映：

        @Configuration        @ConditionalOnProperty(            value = {"spring.mvc.favicon.enabled"},            matchIfMissing = true        )		/* 		 * ResourceLoaderAware是一個標記介面		 * 用於透過ApplicationContext上下文注入ResourceLoader		 * 有setResourceLoader()方法		 */        public static class FaviconConfiguration implements ResourceLoaderAware {            private final ResourceProperties resourceProperties;            /*              * ResourceLoader用於返回Resource物件和ClassLoader物件             * 		- getResource(String location)方法根據提供的location引數返回相應的Resource物件             * 		- getClassLoader()方法則返回載入這些Resource的ClassLoader             */            private ResourceLoader resourceLoader;            public FaviconConfiguration(ResourceProperties resourceProperties) {                this.resourceProperties = resourceProperties;            }            public void setResourceLoader(ResourceLoader resourceLoader) {                this.resourceLoader = resourceLoader;            }			/* 			 * SimpleUrlHandlerMapping是SpringMVC中適應性最強的Handler Mapping類			 * 允許明確指定URL模式和Handler的對映關係.有兩種宣告方式:			 * 		- prop:			 * 		  - key: URL模式			 * 		  — value: Handler的ID或者名字			 * 		- value:			 * 		  - 等號左邊是URL模式			 * 		  - 等號右邊是HandlerID或者名字  			 */            @Bean            public SimpleUrlHandlerMapping faviconHandlerMapping() {                SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();                mapping.setOrder(-2147483647);                mapping.setUrlMap(Collections.singletonMap("**/favicon.ico", this.faviconRequestHandler()));                return mapping;            }

配置喜歡的圖示(標籤的圖示)：

 @Configuration    public static class EnableWebMvcConfiguration extends DelegatingWebMvcConfiguration {

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

 //將所有的WebMvcConfigurer相關的配置都呼叫一遍 public void addViewControllers(ViewControllerRegistry registry) {        Iterator var2 = this.delegates.iterator();        while(var2.hasNext()) {            WebMvcConfigurer delegate = (WebMvcConfigurer)var2.next();            delegate.addViewControllers(registry);        }    }

@Import({DelegatingWebMvcConfiguration.class})public @interface EnableWebMvc {}

@Configurationpublic class DelegatingWebMvcConfiguration extends WebMvcConfigurationSupport {

@Configuration@ConditionalOnWebApplication(    type = Type.SERVLET)@ConditionalOnClass({Servlet.class, DispatcherServlet.class, WebMvcConfigurer.class})@ConditionalOnMissingBean({WebMvcConfigurationSupport.class})	//當容器中沒有此元件時，此自動配置類才生效@AutoConfigureOrder(-2147483638)@AutoConfigureAfter({DispatcherServletAutoConfiguration.class, TaskExecutionAutoConfiguration.class, ValidationAutoConfiguration.class})