SpringBoot学习笔记

朴灿烈づ我的快乐病毒、 2022-12-24 05:50 119阅读 0赞

# 静态资源导入 #

通过源码 WebMvcAutoConfiguation 源码我们可以看出

public void addResourceHandlers(ResourceHandlerRegistry registry) { 
       if (!this.resourceProperties.isAddMappings()) { 
          logger.debug("Default resource handling disabled");
          return;
       }
       Duration cachePeriod = this.resourceProperties.getCache().getPeriod();
       CacheControl cacheControl = this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl();
       if (!registry.hasMappingForPattern("/webjars/**")) { 
          customizeResourceHandlerRegistration(registry.addResourceHandler("/webjars/**")
                .addResourceLocations("classpath:/META-INF/resources/webjars/")
                .setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl));
       }
       String staticPathPattern = this.mvcProperties.getStaticPathPattern();
       if (!registry.hasMappingForPattern(staticPathPattern)) { 
          customizeResourceHandlerRegistration(registry.addResourceHandler(staticPathPattern)
                .addResourceLocations(getResourceLocations(this.resourceProperties.getStaticLocations()))
                .setCachePeriod(getSeconds(cachePeriod)).setCacheControl(cacheControl));
       }
    }

*  可以通过自定义来设置静态资源位置
 *  可以通过webjar访问静态资源
 *  查看getStaticLocations()，我们可以发现
 *      private static final String[] CLASSPATH_RESOURCE_LOCATIONS = {  "classpath:/META-INF/resources/",
              "classpath:/resources/", "classpath:/static/", "classpath:/public/" };
 *  通过这几个路径都可以访问到静态资源
    
        private Resource getIndexHtml(String location) { 
           return this.resourceLoader.getResource(location + "index.html");
        }
 *  全局搜索，双shift
 *  找到indexhtml源码后，我们发现老几样的位置+“index,html”就可以实现访问首页了
    
    # Thymeleaf模板引擎 #
 *  和jsp一样，thymeleaf模板引擎可以让我们在HTML页面中取值等操作
 *      <!DOCTYPE html>
        <html xmlns:th="http://www.thymeleaf.org">
        <head>
            <title>Title</title>
            <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
            <link rel="stylesheet" type="text/css" media="all" href="../../css/gtvg.css" th:href="@{/css/gtvg.css}" />
        
        </head>
 *  页面约束
 *      <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
 *  pom约束
 *  在controller中传值
 *      @Controller
        public class TestController { 
            @RequestMapping("/a")
            public String test(Model model){ 
                model.addAttribute("msg","message");
                return "test";
            }
        }
 *

*  取值，收工
 *  注意，template中的页面只能有controller访问
    
    # 拓展以及装配SpringMVC #
    
    Spring Boot provides auto-configuration for Spring MVC that works well with most applications.
    
    The auto-configuration adds the following features on top of Spring’s defaults:
    
     *  Inclusion of `ContentNegotiatingViewResolver` and `BeanNameViewResolver` beans.
     *  Support for serving static resources, including support for WebJars (covered [later in this document][])).
     *  Automatic registration of `Converter`, `GenericConverter`, and `Formatter` beans.
     *  Support for `HttpMessageConverters` (covered [later in this document][later in this document 1]).
     *  Automatic registration of `MessageCodesResolver` (covered [later in this document][later in this document 2]).
     *  Static `index.html` support.
     *  Custom `Favicon` support (covered [later in this document][later in this document 3]).
     *  Automatic use of a `ConfigurableWebBindingInitializer` bean (covered [later in this document][later in this document 4]).
    
    If you want to keep those Spring Boot MVC customizations and make more [MVC customizations][] (interceptors, formatters, view controllers, and other features), you can add your own `@Configuration` class of type `WebMvcConfigurer` but **without** `@EnableWebMvc`.
    
    If you want to provide custom instances of `RequestMappingHandlerMapping`, `RequestMappingHandlerAdapter`, or `ExceptionHandlerExceptionResolver`, and still keep the Spring Boot MVC customizations, you can declare a bean of type `WebMvcRegistrations` and use it to provide custom instances of those components.
    
    If you want to take complete control of Spring MVC, you can add your own `@Configuration` annotated with `@EnableWebMvc`, or alternatively add your own `@Configuration`\-annotated `DelegatingWebMvcConfiguration` as described in the Javadoc of `@EnableWebMvc`.

[later in this document]: https://docs.spring.io/spring-boot/docs/2.2.5.RELEASE/reference/htmlsingle/#boot-features-spring-mvc-static-content
[later in this document 1]: https://docs.spring.io/spring-boot/docs/2.2.5.RELEASE/reference/htmlsingle/#boot-features-spring-mvc-message-converters
[later in this document 2]: https://docs.spring.io/spring-boot/docs/2.2.5.RELEASE/reference/htmlsingle/#boot-features-spring-message-codes
[later in this document 3]: https://docs.spring.io/spring-boot/docs/2.2.5.RELEASE/reference/htmlsingle/#boot-features-spring-mvc-favicon
[later in this document 4]: https://docs.spring.io/spring-boot/docs/2.2.5.RELEASE/reference/htmlsingle/#boot-features-spring-mvc-web-binding-initializer
[MVC customizations]: https://docs.spring.io/spring/docs/5.2.4.RELEASE/spring-framework-reference/web.html#mvc