【深入理解SpringCloud微服务】Sentinel源码解析——SentinelWebInterceptor拦截器与@SentinelResource注解原理

spring-cloud-starter-alibaba-sentinel的自动装配

当我们的工程需要使用Sentinel时，如果我们引入的时spring-cloud-starter-alibaba-sentinel，那么由于spring-cloud-starter-alibaba-sentinel的使用了SpringBoot的自动装配机制加载了一些核心类，因此是不需要我们做过多复杂的配置的。

META-INF/spring.factories

org.springframework.boot.autoconfigure.EnableAutoConfiguration=\
# SentinelWebAutoConfiguration里面会加载SentinelWebInterceptor
com.alibaba.cloud.sentinel.SentinelWebAutoConfiguration,\
...
# SentinelAutoConfiguration里面会加载SentinelResourceAspect
com.alibaba.cloud.sentinel.custom.SentinelAutoConfiguration,\
...

SentinelWebAutoConfiguration里面会加载SentinelWebInterceptor，它使得Sentinel基于拦截器的规则校验生效。然后SentinelWebMvcConfigurer会把SentinelWebInterceptor注册到SpringMVC的拦截器链中。

@Configuration(proxyBeanMethods = false)
...
public class SentinelWebAutoConfiguration implements WebMvcConfigurer {
   

	...

	@Bean
	@ConditionalOnProperty(name = "spring.cloud.sentinel.filter.enabled",
			matchIfMissing = true)
	public SentinelWebInterceptor sentinelWebInterceptor(
			SentinelWebMvcConfig sentinelWebMvcConfig) {
   
		return new SentinelWebInterceptor(sentinelWebMvcConfig);
	}

	...

	@Bean
	@ConditionalOnProperty(name = "spring.cloud.sentinel.filter.enabled",
			matchIfMissing = true)
	public SentinelWebMvcConfigurer sentinelWebMvcConfigurer() {
   
		return new SentinelWebMvcConfigurer();
	}

}

SentinelWebMvcConfigurer#addInterceptors(InterceptorRegistry)

	@Override
	public void addInterceptors(InterceptorRegistry registry) {
   
		...
		SentinelProperties.Filter filterConfig = sentinelProperties.getFilter();
		// sentinelWebInterceptorOptional.get()取到