SpringBoot与Web

先在idea中选择场景
SpringBoot已经默认将这些常见配置好了，我们只需要在配置文件中指定少量配置就可以运行起来
然后我们可以开始编写业务代码了

SpringBoot与静态资源

WebMvcAutoConfiguration

打开WebMvcAutoConfiguration.java

@Override
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));
    }
}

配置jquery

所有/webjars/下的资源，都去classpath:/MEFA-INF/resources/webjars/找
在Webjars中选择Maven,然后就可以导入你想要jquery的依赖了
比方安装了这个以后就可以通过下面的地址访问jquery了localhost:8080/webjars/jquery/3.3.1/jquery.js

<dependency>
    <groupId>org.webjars</groupId>
    <artifactId>jquery</artifactId>
    <version>3.5.0</version>
</dependency>

默认映射

ResourceProperties 可以设置静态资源的配置，如缓存时间

1 2	@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false) public class ResourceProperties {

还会在下面的路径中找(静态资源的文件夹)
比方说你要访问一个localhost:8080/myjs.js,如果找不到的话，就在下面的文件夹中寻找

1 2	private static final String[] CLASSPATH_RESOURCE_LOCATIONS = { "classpath:/META-INF/resources/", "classpath:/resources/", "classpath:/static/", "classpath:/public/" };

欢迎界面

欢迎页面, 静态资源文件夹的/index.html, 见下面的代码

@Bean
public WelcomePageHandlerMapping welcomePageHandlerMapping(ApplicationContext applicationContext,
        FormattingConversionService mvcConversionService, ResourceUrlProvider mvcResourceUrlProvider) {
    WelcomePageHandlerMapping welcomePageHandlerMapping = new WelcomePageHandlerMapping(
            new TemplateAvailabilityProviders(applicationContext), applicationContext, getWelcomePage(),
            this.mvcProperties.getStaticPathPattern());
    welcomePageHandlerMapping.setInterceptors(getInterceptors(mvcConversionService, mvcResourceUrlProvider));
    return welcomePageHandlerMapping;
}
    private Optional<Resource> getWelcomePage() {
    String[] locations = getResourceLocations(this.resourceProperties.getStaticLocations());
    return Arrays.stream(locations).map(this::getIndexHtml).filter(this::isReadable).findFirst();
}

private Resource getIndexHtml(String location) {
    return this.resourceLoader.getResource(location + "index.html");
}