RewriteResponseHeader Filter

The RewriteResponseHeader filter takes name, regexp, and replacement parameters. It uses Java regular expressions for a flexible way to rewrite the response header value. The following example configures a RewriteResponseHeader filter:

application.yml
spring:
  cloud:
    gateway:
      mvc:
        routes:
        - id: rewriteresponseheader_route
          uri: https://example.org
          filters:
          - RewriteResponseHeader=X-Response-Red, , password=[^&]+, password=***
GatewaySampleApplication.java
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> gatewayRouterFunctionsRewriteResponseHeader() {
        return route("rewriteresponseheader_route")
                .GET("/**", http("https://example.org"))
                .after(rewriteResponseHeader("X-Request-Red", "password=[^&]+", "password=***"))
            .build();
    }
}

For a header value of /42?user=ford&password=omg!what&flag=true, it is set to /42?user=ford&password=***&flag=true after making the downstream request. You must use $\ to mean $ because of the YAML specification in application.yml.