前言
WebMvcAutoConfiguration中有一些常用的与静态资源相关的配置项，本文回顾一下其中原理。本文中SpringBoot版本号为2.7.5。
原文地址：https://xuedongyun.cn/post/3386/
静态资源配置原理
WebMvcAutoConfiguration
SpringBoot启动会自动加载WebMvcAutoConfiguration类。（具体原因可以查看我之前的博客：SpringBootApplication注解背后的原理），我们首先看看这个自动配置类生效的条件：
1
2
3
4
5
6
7
8
9
10
11
12
13
|
@AutoConfiguration(after = { DispatcherServletAutoConfiguration.class,
TaskExecutionAutoConfiguration.class,
ValidationAutoConfiguration.class })
@ConditionalOnWebApplication(type = Type.SERVLET)
@ConditionalOnClass({ Servlet.class, DispatcherServlet.class, WebMvcConfigurer.class })
@ConditionalOnMissingBean(WebMvcConfigurationSupport.class)
@AutoConfigureOrder(Ordered.HIGHEST_PRECEDENCE + 10)
public class WebMvcAutoConfiguration {
}
|
WebMvcAutoConfigurationAdapter
WebMvcAutoConfiguration类中，还有一个静态类WebMvcAutoConfigurationAdapter。它还绑定了两个属性类WebMvcProperties和WebProperties，我们可以在配置文件中更改相应配置项的属性，实现对某些功能的自定义
1
2
3
4
5
| @Configuration(proxyBeanMethods = false)
@Import(EnableWebMvcConfiguration.class)
@EnableConfigurationProperties({ WebMvcProperties.class, WebProperties.class })
@Order(0)
public static class WebMvcAutoConfigurationAdapter implements WebMvcConfigurer, ServletContextAware {
|
1
2
3
4
5
| @ConfigurationProperties(prefix = "spring.mvc")
public class WebMvcProperties {}
@ConfigurationProperties("spring.web")
public class WebProperties {}
|
WebMvcAutoConfigurationAdapter只有一个构造函数，所有值从容器中获取
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
| public WebMvcAutoConfigurationAdapter(
// 两个属性类
WebProperties webProperties,
WebMvcProperties mvcProperties,
// Spring的IOC容器
ListableBeanFactory beanFactory,
// 所有的messageConverter，此处不涉及
ObjectProvider<HttpMessageConverters> messageConvertersProvider,
// 所有的资源自定义器，重点
ObjectProvider<ResourceHandlerRegistrationCustomizer> resourceHandlerRegistrationCustomizerProvider,
// DispathcerServlet能处理的所有路径，此处不涉及
ObjectProvider<DispatcherServletPath> dispatcherServletPath,
// 应用注册的原生Servlet，Filter...此处不涉及
ObjectProvider<ServletRegistrationBean<?>> servletRegistrations
) {
this.resourceProperties = webProperties.getResources();
this.mvcProperties = mvcProperties;
}
|
在WebMvcAutoConfigurationAdapter类中，有一些与资源相关的核心方法
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
| @Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
if (!this.resourceProperties.isAddMappings()) {
logger.debug("Default resource handling disabled");
return;
}
addResourceHandler(registry, "/webjars/**", "classpath:/META-INF/resources/webjars/");
addResourceHandler(registry, this.mvcProperties.getStaticPathPattern(), (registration) -> {
registration.addResourceLocations(this.resourceProperties.getStaticLocations());
if (this.servletContext != null) {
ServletContextResource resource =
new ServletContextResource(this.servletContext, SERVLET_LOCATION);
registration.addResourceLocations(resource);
}
});
}
|
1
2
3
4
5
6
7
8
9
10
|
private void addResourceHandler(ResourceHandlerRegistry registry, String pattern,
Consumer<ResourceHandlerRegistration> customizer) {
...
registration.setCachePeriod(getSeconds(this.resourceProperties.getCache().getPeriod()));
registration.setCacheControl(this.resourceProperties.getCache().getCachecontrol().toHttpCacheControl());
registration.setUseLastModified(this.resourceProperties.getCache().isUseLastModified());
...
}
|
前面提到的配置项
1
2
3
4
5
6
7
8
9
| spring:
web:
resources:
add-mappings: false
static-locations: [classpath:/haha/, classpath:/page/]
cache:
period: 3600
mvc:
static-path-pattern: /resources/**
|
