应用程序的配置文件是：

spring:
  cloud:
    gateway:
      routes:
        - id: gateway-server
          uri: http://localhost:8081
          predicates:
            - Path=/**
          filters:
            - SomeFilterFactory

使用的过滤器是：

public class SomeFilterFactory
        extends AbstractGatewayFilterFactory<SomeFilterFactory.SomeConfig> {


    public SomeFilterFactory() {
        super(SomeFilterFactory.SomeConfig.class);
    }

    @Override
    public GatewayFilter apply(SomeFilterFactory.SomeConfig config) {

        return (exchange, chain) -> {
            ServerHttpRequest request = exchange.getRequest();
            String someHeader = request.getHeaders().getFirst("someHeader");
            // do your things here
            return chain.filter(exchange);
        };
    }

    public static class SomeConfig {
        // your config if required
        // or use name value config
    }

我的要求是在下游传递之前验证每个传入请求中传递的标头值。