Support response-timeout property as a String

Fixes gh-2581

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

@@ -260,17 +260,32 @@ public class NettyRoutingFilter implements GlobalFilter, Ordered {
 	}
 
 	private Duration getResponseTimeout(Route route) {
-		Object responseTimeoutAttr = route.getMetadata().get(RESPONSE_TIMEOUT_ATTR);
-		if (responseTimeoutAttr != null && responseTimeoutAttr instanceof Number) {
-			Long routeResponseTimeout = ((Number) responseTimeoutAttr).longValue();
-			if (routeResponseTimeout >= 0) {
-				return Duration.ofMillis(routeResponseTimeout);
-			}
-			else {
-				return null;
+		try {
+			if (route.getMetadata().containsKey(RESPONSE_TIMEOUT_ATTR)) {
+				Long routeResponseTimeout = getLong(route.getMetadata().get(RESPONSE_TIMEOUT_ATTR));
+				if (routeResponseTimeout != null && routeResponseTimeout >= 0) {
+					return Duration.ofMillis(routeResponseTimeout);
+				}
+				else {
+					return null;
+				}
 			}
 		}
+		catch (NumberFormatException e) {
+			// ignore number format and use global default
+		}
 		return properties.getResponseTimeout();
 	}
 
+	static Long getLong(Object responseTimeoutAttr) {
+		Long responseTimeout = null;
+		if (responseTimeoutAttr instanceof Number) {
+			responseTimeout = ((Integer) responseTimeoutAttr).longValue();
+		}
+		else if (responseTimeoutAttr != null) {
+			responseTimeout = Long.parseLong(responseTimeoutAttr.toString());
+		}
+		return responseTimeout;
+	}
+
 }

spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/filter/NettyRoutingFilterCompatibleTests.java

@@ -30,6 +30,7 @@ import org.springframework.test.context.ActiveProfiles;
 import org.springframework.web.server.ServerWebExchange;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
 
 /**
@@ -51,6 +52,14 @@ class NettyRoutingFilterCompatibleTests extends BaseWebClientTests {
 		assertThat(NettyRoutingFilter.getInteger(5)).isEqualTo(5);
 	}
 
+	@Test
+	void getLongHandlesStringAndNumber() {
+		assertThat(NettyRoutingFilter.getLong("5")).isEqualTo(5);
+		assertThat(NettyRoutingFilter.getLong(5)).isEqualTo(5);
+		assertThat(NettyRoutingFilter.getLong(null)).isNull();
+		assertThatThrownBy(() -> NettyRoutingFilter.getLong("notanumber")).isInstanceOf(NumberFormatException.class);
+	}
+
 	@Test
 	void shouldApplyResponseTimeoutPerRoute() {
 		testClient.get().uri("/route/delay/2").exchange().expectStatus().isEqualTo(HttpStatus.GATEWAY_TIMEOUT)

spring-cloud-gateway-server/src/test/java/org/springframework/cloud/gateway/filter/NettyRoutingFilterIntegrationTests.java

@@ -120,6 +120,12 @@ public class NettyRoutingFilterIntegrationTests extends BaseWebClientTests {
 				.hasMessageContaining("Timeout on blocking read for 5000000000 NANOSECONDS");
 	}
 
+	@Test
+	public void shouldApplyResponseTimeoutForPlaceholder() {
+		testClient.get().uri("/responseheaders/200").header("Host", "www.responsetimeoutplaceholder.org").exchange()
+				.expectStatus().isEqualTo(HttpStatus.OK);
+	}
+
 	@Test
 	public void shouldApplyGlobalResponseTimeoutForInvalidRouteTimeoutValue() {
 		testClient.get().uri("/invalidRoute/delay/5").exchange().expectStatus().isEqualTo(HttpStatus.GATEWAY_TIMEOUT)

spring-cloud-gateway-server/src/test/resources/application-netty-routing-filter.yml

@@ -2,6 +2,8 @@ test:
   hostport: httpbin.org:80
   uri: lb://testservice
 
+my.timeout: 3000
+
 server:
   error:
     include-message: always
@@ -71,6 +73,15 @@ spring:
           metadata:
             response-timeout: 1000
 
+        # =====================================
+        - id: per_route_response_timeout_placeholder
+          uri: ${test.uri}
+          predicates:
+            - Host=**.responsetimeoutplaceholder.org
+            - Path=/responseheaders/**
+          metadata:
+            response-timeout: ${my.timeout}
+
         # =====================================
         # should be last and not follow alphabetical order
         - id: default_path_to_httpbin