Spring Cloud Gateway注入报头

Question

在GatewayFilter中，我试图将一个头注入到请求中，如下所示。

java.lang.UnsupportedOperationException: null
at java.util.Collections$UnmodifiableMap.computeIfAbsent(Collections.java:1535) ~[na:1.8.0_111]
at org.springframework.http.HttpHeaders.add(HttpHeaders.java:1425) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at com.trimble.sample.springcloudgateway.filter.AuthGatewayFilter.filter(AuthGatewayFilter.java:30) ~[classes/:na]
at org.springframework.cloud.gateway.filter.OrderedGatewayFilter.filter(OrderedGatewayFilter.java:44) ~[spring-cloud-gateway-core-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.cloud.gateway.handler.FilteringWebHandler$DefaultGatewayFilterChain.filter(FilteringWebHandler.java:103) ~[spring-cloud-gateway-core-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.cloud.gateway.filter.NettyWriteResponseFilter.filter(NettyWriteResponseFilter.java:62) ~[spring-cloud-gateway-core-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.cloud.gateway.handler.FilteringWebHandler$GatewayFilterAdapter.filter(FilteringWebHandler.java:121) ~[spring-cloud-gateway-core-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.cloud.gateway.filter.OrderedGatewayFilter.filter(OrderedGatewayFilter.java:44) ~[spring-cloud-gateway-core-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]
at org.springframework.cloud.gateway.handler.FilteringWebHandler$DefaultGatewayFilterChain.filter(FilteringWebHandler.java:103) ~[spring-cloud-gateway-core-2.0.0.BUILD-SNAPSHOT.jar:2.0.0.BUILD-SNAPSHOT]

Answer 1

你可以看看

org.springframework.cloud.gateway.filter.factory.*gatewayfilterfactory

有许多有用的网关过滤器实现。

org.springframework.cloud.gateway.filter.factory.addrequestheadergatewayfilterfactory

有一个标准的实现。

public class AddRequestHeaderGatewayFilterFactory extends AbstractNameValueGatewayFilterFactory {

    @Override
    public GatewayFilter apply(NameValueConfig config) {
        return (exchange, chain) -> {
            ServerHttpRequest request = exchange.getRequest().mutate()
                    .header(config.getName(), config.getValue())
                    .build();

            return chain.filter(exchange.mutate().request(request).build());
        };
    }
}