Allows use of custom http status codes.

fixes gh-284

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/NettyRoutingFilter.java

@@ -22,7 +22,6 @@ import java.util.List;
 
 import io.netty.handler.codec.http.DefaultHttpHeaders;
 import io.netty.handler.codec.http.HttpMethod;
-import org.springframework.cloud.gateway.filter.headers.HttpHeadersFilter.Type;
 import reactor.core.publisher.Mono;
 import reactor.ipc.netty.NettyPipeline;
 import reactor.ipc.netty.http.client.HttpClient;
@@ -30,10 +29,12 @@ import reactor.ipc.netty.http.client.HttpClientRequest;
 
 import org.springframework.beans.factory.ObjectProvider;
 import org.springframework.cloud.gateway.filter.headers.HttpHeadersFilter;
+import org.springframework.cloud.gateway.filter.headers.HttpHeadersFilter.Type;
 import org.springframework.core.Ordered;
 import org.springframework.core.io.buffer.NettyDataBuffer;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.server.reactive.AbstractServerHttpResponse;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
 import org.springframework.web.server.ServerWebExchange;
@@ -117,7 +118,15 @@ public class NettyRoutingFilter implements GlobalFilter, Ordered {
 					this.headersFilters.getIfAvailable(), headers, exchange, Type.RESPONSE);
 			
 			response.getHeaders().putAll(filteredResponseHeaders);
-			response.setStatusCode(HttpStatus.valueOf(res.status().code()));
+			HttpStatus status = HttpStatus.resolve(res.status().code());
+			if (status != null) {
+				response.setStatusCode(status);
+			} else if (response instanceof AbstractServerHttpResponse) {
+				// https://jira.spring.io/browse/SPR-16748
+				((AbstractServerHttpResponse) response).setStatusCodeValue(res.status().code());
+			} else {
+				throw new IllegalStateException("Unable to set status code on response: " +res.status().code()+", "+response.getClass());
+			}
 
 			// Defer committing the response until all route filters have run
 			// Put client response as ServerWebExchange attribute and write response later NettyWriteResponseFilter

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/filter/factory/SetStatusGatewayFilterFactory.java

@@ -20,14 +20,15 @@ package org.springframework.cloud.gateway.filter.factory;
 import java.util.Arrays;
 import java.util.List;
 
+import reactor.core.publisher.Mono;
+
 import org.springframework.cloud.gateway.filter.GatewayFilter;
 import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.server.reactive.AbstractServerHttpResponse;
 
 import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.setResponseStatus;
 
-import reactor.core.publisher.Mono;
-
 /**
  * @author Spencer Gibb
  */
@@ -47,6 +48,12 @@ public class SetStatusGatewayFilterFactory extends AbstractGatewayFilterFactory<
 	@Override
 	public GatewayFilter apply(Config config) {
 		final HttpStatus status = ServerWebExchangeUtils.parse(config.status);
+		final Integer intStatus;
+		if (status == null) {
+			intStatus = Integer.parseInt(config.status);
+		} else {
+			intStatus = null;
+		}
 		return (exchange, chain) -> {
 
 			// option 1 (runs in filter order)
@@ -61,7 +68,11 @@ public class SetStatusGatewayFilterFactory extends AbstractGatewayFilterFactory<
 				// check not really needed, since it is guarded in setStatusCode,
 				// but it's a good example
 				if (!exchange.getResponse().isCommitted()) {
-					setResponseStatus(exchange, status);
+					if (status != null) { // standard status
+						setResponseStatus(exchange, status);
+					} else if (intStatus != null && exchange.getResponse() instanceof AbstractServerHttpResponse) { //non-standard
+						((AbstractServerHttpResponse)exchange.getResponse()).setStatusCodeValue(intStatus);
+					}
 				}
 			}));
 		};

spring-cloud-gateway-core/src/main/java/org/springframework/cloud/gateway/support/ServerWebExchangeUtils.java

@@ -83,7 +83,7 @@ public class ServerWebExchangeUtils {
 
 		try {
 			int status = Integer.parseInt(statusString);
-			httpStatus = HttpStatus.valueOf(status);
+			httpStatus = HttpStatus.resolve(status);
 		} catch (NumberFormatException e) {
 			// try the enum string
 			httpStatus = HttpStatus.valueOf(statusString.toUpperCase());

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/filter/factory/SetStatusGatewayFilterFactoryTests.java

@@ -19,21 +19,27 @@ package org.springframework.cloud.gateway.filter.factory;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
+
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.cloud.gateway.route.RouteLocator;
+import org.springframework.cloud.gateway.route.builder.RouteLocatorBuilder;
 import org.springframework.cloud.gateway.test.BaseWebClientTests;
+import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Import;
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.junit4.SpringRunner;
-import org.springframework.web.reactive.function.client.ClientResponse;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
-import static org.springframework.cloud.gateway.test.TestUtils.assertStatus;
-
-import reactor.core.publisher.Mono;
-import reactor.test.StepVerifier;
 
 @RunWith(SpringRunner.class)
 @SpringBootTest(webEnvironment = RANDOM_PORT)
@@ -51,23 +57,45 @@ public class SetStatusGatewayFilterFactoryTests extends BaseWebClientTests {
 	}
 
 	private void setStatusStringTest(String host, HttpStatus status) {
-		Mono<ClientResponse> result = webClient.get()
+		testClient.get()
 				.uri("/headers")
 				.header("Host", host)
-				.exchange();
+				.exchange()
+				.expectStatus().isEqualTo(status);
+	}
 
-		StepVerifier.create(result)
-				.consumeNextWith(
-						response -> {
-							assertStatus(response, status);
-						})
-				.expectComplete()
-				.verify(DURATION);
+	@Test
+	public void nonStandardCodeWorks() {
+		HttpHeaders headers = new HttpHeaders();
+		headers.set(HttpHeaders.HOST, "www.setcustomstatus.org");
+		ResponseEntity<String> response = new TestRestTemplate().exchange(baseUri + "/headers",
+				HttpMethod.GET, new HttpEntity<>(headers), String.class);
+		assertThat(response.getStatusCodeValue()).isEqualTo(432);
+
+		// https://jira.spring.io/browse/SPR-16748
+		/*testClient.get()
+				.uri("/status/432")
+				.exchange()
+				.expectStatus().isEqualTo(432)
+				.expectBody(String.class).isEqualTo("Failed with 432");*/
 	}
 
 	@EnableAutoConfiguration
 	@SpringBootConfiguration
 	@Import(DefaultTestConfig.class)
-	public static class TestConfig { }
+	public static class TestConfig {
+
+		@Value("${test.uri}")
+		String uri;
+
+		@Bean
+		public RouteLocator myRouteLocator(RouteLocatorBuilder builder) {
+			return builder.routes()
+					.route("test_custom_http_status", r -> r.host("*.setcustomstatus.org")
+							.filters(f -> f.setStatus(432))
+							.uri(uri))
+					.build();
+		}
+	}
 
 }

spring-cloud-gateway-core/src/test/java/org/springframework/cloud/gateway/test/HttpStatusTests.java

@@ -26,8 +26,10 @@ import org.springframework.boot.SpringApplication;
 import org.springframework.boot.SpringBootConfiguration;
 import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.web.client.TestRestTemplate;
 import org.springframework.context.annotation.Import;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.context.junit4.SpringRunner;
 import org.springframework.web.bind.annotation.RequestMapping;
@@ -51,6 +53,20 @@ public class HttpStatusTests extends BaseWebClientTests {
 				.expectBody(String.class).isEqualTo("Failed with 404");
 	}
 
+	@Test
+	public void nonStandardCodeWorks() {
+		ResponseEntity<String> response = new TestRestTemplate().getForEntity(baseUri + "/status/432", String.class);
+		assertThat(response.getStatusCodeValue()).isEqualTo(432);
+		assertThat(response.getBody()).isEqualTo("Failed with 432");
+
+
+		/*testClient.get()
+				.uri("/status/432")
+				.exchange()
+				.expectStatus().isEqualTo(432)
+				.expectBody(String.class).isEqualTo("Failed with 432");*/
+	}
+
 	@Test
 	public void serverErrorResponseWorks() {
 		testClient.get()