一、创建Web项目
创建的时候勾选对应web选项即可，会自动引入相应的starter，pom如下：
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
里面的具体依赖不一一展开了。
二、SpringBoot的Web自动配置
经过前面的研究，知道主要是springboot为我们引入了org.springframework.boot.autoconfigure.web包的
1.自动配置类：xxxxAutoConfiguration帮我们给容器中自动配置组件；
2.配置文件封装类：xxxxProperties:配置类来封装配置文件的内容；
eg：DispatcherServletAutoConfiguration、WebMvcAutoConfiguration和WebMvcProperties、ResourceProperties
具体自动配置帮我们做了什么可以看xxxxAutoConfiguration，我们配置文件能配置什么属性可以看xxxxProperties。
三、springboot web的静态资源映射规则
1.ResourceProperties
@ConfigurationProperties(prefix = "spring.resources", ignoreUnknownFields = false)
public class ResourceProperties { private static final String[] CLASSPATH_RESOURCE_LOCATIONS = {
"classpath:/META-INF/resources/", "classpath:/resources/",
"classpath:/static/", "classpath:/public/" }; /**
* Locations of static resources. Defaults to classpath:[/META-INF/resources/,
* /resources/, /static/, /public/].
*/
private String[] staticLocations = CLASSPATH_RESOURCE_LOCATIONS; /**
* Whether to enable default resource handling.
*/
private boolean addMappings = true; private final Chain chain = new Chain(); private final Cache cache = new Cache(); public String[] getStaticLocations() {
return this.staticLocations;
} public void setStaticLocations(String[] staticLocations) {
this.staticLocations = appendSlashIfNecessary(staticLocations);
} private String[] appendSlashIfNecessary(String[] staticLocations) {
String[] normalized = new String[staticLocations.length];
for (int i = 0; i < staticLocations.length; i++) {
String location = staticLocations[i];
normalized[i] = location.endsWith("/") ? location : location + "/";
}
return normalized;
}
可以看到springboot自动配置默认回到
"classpath:/META-INF/resources/",
"classpath:/resources/",
"classpath:/static/",
"classpath:/public/"
目录下寻找静态资源。
2.WebMvcAuotConfiguration
@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
if (!this.resourceProperties.isAddMappings()) {
logger.debug("Default resource handling disabled");
return;
}
Integer cachePeriod = this.resourceProperties.getCachePeriod();
if (!registry.hasMappingForPattern("/webjars/**")) {
customizeResourceHandlerRegistration(
registry.addResourceHandler("/webjars/**")
.addResourceLocations(
"classpath:/META-INF/resources/webjars/")
.setCachePeriod(cachePeriod));
}
String staticPathPattern = this.mvcProperties.getStaticPathPattern();
//静态资源文件夹映射
if (!registry.hasMappingForPattern(staticPathPattern)) {
customizeResourceHandlerRegistration(
registry.addResourceHandler(staticPathPattern)
.addResourceLocations(
this.resourceProperties.getStaticLocations())
.setCachePeriod(cachePeriod));
}
} //配置欢迎页映射
@Bean
public WelcomePageHandlerMapping welcomePageHandlerMapping(
ResourceProperties resourceProperties) {
return new WelcomePageHandlerMapping(resourceProperties.getWelcomePage(),
this.mvcProperties.getStaticPathPattern());
}
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");
}
//配置喜欢的图标
@Configuration
@ConditionalOnProperty(value = "spring.mvc.favicon.enabled", matchIfMissing = true)
public static class FaviconConfiguration { private final ResourceProperties resourceProperties; public FaviconConfiguration(ResourceProperties resourceProperties) {
this.resourceProperties = resourceProperties;
} @Bean
public SimpleUrlHandlerMapping faviconHandlerMapping() {
SimpleUrlHandlerMapping mapping = new SimpleUrlHandlerMapping();
mapping.setOrder(Ordered.HIGHEST_PRECEDENCE + 1);
//所有 **/favicon.ico
mapping.setUrlMap(Collections.singletonMap("**/favicon.ico",
faviconRequestHandler()));
return mapping;
} @Bean
public ResourceHttpRequestHandler faviconRequestHandler() {
ResourceHttpRequestHandler requestHandler = new ResourceHttpRequestHandler();
requestHandler
.setLocations(this.resourceProperties.getFaviconLocations());
return requestHandler;
} }
1.webjars：允许我们以jar的方式引入静态资源（http://www.webjars.org/），如jQuery
<!--引入jquery-webjar-->在访问的时候只需要写webjars下面资源的名称即可
<dependency>
<groupId>org.webjars</groupId>
<artifactId>jquery</artifactId>
<version>3.3.1</version>
</dependency>
访问路径：localhost:8080/webjars/jquery/3.3.1/jquery.js
2.欢迎页，默认静态资源根目录/ndex.html
3.页面标签页图标，默认静态资源根目录/favicon.ico
四、Web自定义设置
以上这些都是了解到的默认配置，但有的时候不满足实际需求需要我们自定义配置，下节边自定义边研究原理。