AddResponseHeader Filter

The AddResponseHeader Filter takes a name and value parameter. The following example configures an AddResponseHeader filter:

application.yml
spring:
  cloud:
    gateway:
      mvc:
        routes:
        - id: add_response_header_route
          uri: https://example.org
          predicates:
          - Path=/anything/addresheader
          filters:
          - AddResponseHeader=X-Response-Red, Blue
GatewaySampleApplication.java
import static org.springframework.cloud.gateway.server.mvc.filter.BeforeFilterFunctions.uri;
import static org.springframework.cloud.gateway.server.mvc.filter.AfterFilterFunctions.addResponseHeader;
import static org.springframework.cloud.gateway.server.mvc.handler.GatewayRouterFunctions.route;
import static org.springframework.cloud.gateway.server.mvc.handler.HandlerFunctions.http;

@Configuration
class RouteConfiguration {

    @Bean
    public RouterFunction<ServerResponse> gatewayRouterFunctionsAddRespHeader() {
        return route("add_response_header_route")
            .GET("/anything/addresheader", http())
            .before(uri("https://example.org"))
            .after(addResponseHeader("X-Response-Red", "Blue"))
            .build();
    }
}

This adds X-Response-Red:Blue header to the downstream response’s headers for all matching requests.

AddResponseHeader is aware of URI variables used to match a path or host. URI variables may be used in the value and are expanded at runtime. The following example configures an AddResponseHeader filter that uses a variable:

GatewaySampleApplication.java
import static org.springframework.cloud.gateway.server.mvc.filter.BeforeFilterFunctions.uri;
import static org.springframework.cloud.gateway.server.mvc.filter.AfterFilterFunctions.addResponseHeader;
import static org.springframework.cloud.gateway.server.mvc.handler.GatewayRouterFunctions.route;
import static org.springframework.cloud.gateway.server.mvc.handler.HandlerFunctions.http;
import static org.springframework.cloud.gateway.server.mvc.predicate.GatewayRequestPredicates.host;

@Configuration
class RouteConfiguration {

    @Bean
    public RouterFunction<ServerResponse> gatewayRouterFunctionsAddRespHeader() {
        return route("add_response_header_route")
            .route(host("{segment}.myhost.org"), http())
            .before(uri("https://example.org"))
            .after(addResponseHeader("foo", "bar-{segment}"))
            .build();
    }
}