Springboot之Web开发：静态资源

柔情只为你懂 2022-05-16 10:23 221阅读 0赞

### 1、使用Springboot进行Web开发 ###

1）创建Springboot应用，选中我们需要的模块；

2）Springboot已经默认将这些场景配置好了，只需要在配置文件中指定少量配置就可以运行起来；

3）自己编写业务代码；

### 2、自动配置原理（自动配置模块） ###

Springboot帮我们配置了什么？能不能修改？能修改哪些配置？能不能扩展？

> **xxxxAutoConfiguration**：帮我们给容器中自动配置组件；  
> **xxxxProperties**:配置类来封装配置文件的内容；

### 3、Springboot对静态资源的映射规则  ###

@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
    public class ResourceProperties implements ResourceLoaderAware {
    //可以设置和静态资源有关的参数，缓存时间等

WebMvcAuotConfiguration：
    
    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));
                    }
                    //静态资源文件夹映射
                    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));
                    }
    
                }
            }
    
    
    
    //配置欢迎页映射
    @Bean
    public WelcomePageHandlerMapping welcomePageHandlerMapping(ApplicationContext     
          applicationContext) {
                return new WelcomePageHandlerMapping(new TemplateAvailabilityProviders(applicationContext), applicationContext, this.getWelcomePage(), this.mvcProperties.getStaticPathPattern());
            }

1）所有 /webjars/\*\*，都去 classpath:/META-INF/resources/webjars/ 找资源

webjars：以jar包的方式引入静态资源文件（[http://www.webjars.org/][http_www.webjars.org]）

![70][]

引入依赖

<dependency>
    			<groupId>org.webjars</groupId>
    			<artifactId>jquery</artifactId>
    			<version>3.3.1-1</version>
    		</dependency>

在访问的时候只需要写webjars下面资源的名称就好了

![70 1][]

那么可以通过 localhost:8080/webjars/jquery/3.3.1-1/jquery.js 访问jQuery的内容

![70 2][]

2）/\*\* ：访问当前项目的任何资源（静态资源的文件夹）

> "classpath:/META‐INF/resources/",  
> "classpath:/resources/",  
> "classpath:/static/",  
> "classpath:/public/"  
> "/"：当前项目的根路径

![70 3][]

![70 4][]

localhost:8080/abc——>去静态资源文件夹里找abc  
访问

![70 5][]

localhost:8080/asserts/js/Chart.min.js

![70 6][]

3）欢迎页：静态资源文件夹下的所有index.html界面，被 “/\*\*”映射

localhost:8080/ ——>就会去找静态资源文件夹下的index页面

4）图标映射， 所有的 \*\*/favicon.ico都是在静态资源文件夹下找

//配置喜欢的图标  
     @Configuration
            @ConditionalOnProperty(
                value = {"spring.mvc.favicon.enabled"},
                matchIfMissing = true
            )
            public static class FaviconConfiguration implements ResourceLoaderAware {
                private final ResourceProperties resourceProperties;
                private ResourceLoader resourceLoader;
    
                public FaviconConfiguration(ResourceProperties resourceProperties) {
                    this.resourceProperties = resourceProperties;
                }
    
                public void setResourceLoader(ResourceLoader resourceLoader) {
                    this.resourceLoader = resourceLoader;
                }
    
                @Bean
                public SimpleUrlHandlerMapping faviconHandlerMapping() {
                    SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();
                    mapping.setOrder(-2147483647);
                    mapping.setUrlMap(Collections.singletonMap("**/favicon.ico", this.faviconRequestHandler()));
                    return mapping;
                }
    
                @Bean
                public ResourceHttpRequestHandler faviconRequestHandler() {
                    ResourceHttpRequestHandler requestHandler = new ResourceHttpRequestHandler();
                    requestHandler.setLocations(this.resolveFaviconLocations());
                    return requestHandler;
                }
    
                private List<Resource> resolveFaviconLocations() {
                    String[] staticLocations = WebMvcAutoConfiguration.WebMvcAutoConfigurationAdapter.getResourceLocations(this.resourceProperties.getStaticLocations());
                    List<Resource> locations = new ArrayList(staticLocations.length + 1);
                    Stream var10000 = Arrays.stream(staticLocations);
                    ResourceLoader var10001 = this.resourceLoader;
                    this.resourceLoader.getClass();
                    var10000.map(var10001::getResource).forEach(locations::add);
                    locations.add(new ClassPathResource("/"));
                    return Collections.unmodifiableList(locations);
                }
            }

同时这些配置静态资源的路径也可以在配置文件中设置

#如果有多个配置就用逗号分隔
    spring.resources.static-locations=classpath:/hello/,classpath:/...

[http_www.webjars.org]: http://www.webjars.org/
[70]: /images/20220516/d4e204d68ca14ea3aa024a8765830b9d.png
[70 1]: /images/20220516/a47598c7f27d44e593083f1cc01341a3.png
[70 2]: /images/20220516/22b4b13b69a5492dbbadd9cc1edf9d52.png
[70 3]: /images/20220516/cfac27e986ae48d09228de9cd431d65b.png
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[70 6]: /images/20220516/16dd6121091947cc9065466001945367.png