我们放弃了在React式/Webflux配置上使用约束验证器的尝试。
我们最终使用了与大多数RestController注解（如AuthenticationPrincipal，PathVariable等）相同的机制，通过创建我们自己的注解并为处理注解类的HandlerMethodArgumentResolver类型创建bean：

import org.springframework.web.reactive.HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE
import java.security.Principal
...
class MethodAnnotationValidator<T : Annotation>(
    adapterRegistry: ReactiveAdapterRegistry,
    private val annotation: Class<T>,
    private val validator: (Principal, String) -> Mono<Any>,
) : HandlerMethodArgumentResolver {
    // compose this resolver to fetch the Auth context
    private val principal = PrincipalMethodArgumentResolver(adapterRegistry)
    // path var resolver isn't composable, next best thing
    private val pathParam = { paramName: String, exchange: ServerWebExchange -> exchange
        .getAttributeOrDefault(URI_TEMPLATE_VARIABLES_ATTRIBUTE, emptyMap<Any, Any>())
        .get(paramName)!!}
    
   // resolve Principal and PathParam and call validator() 
   // inside resolveArgument() override
...

字符串