diff --git a/src/main/java/org/springframework/cloud/gateway/GatewayFilter.java b/src/main/java/org/springframework/cloud/gateway/GatewayFilter.java
index 237725c37..ad8b632f2 100644
--- a/src/main/java/org/springframework/cloud/gateway/GatewayFilter.java
+++ b/src/main/java/org/springframework/cloud/gateway/GatewayFilter.java
@@ -31,6 +31,9 @@ import reactor.core.publisher.Mono;
  */
 public interface GatewayFilter {
 
+	String GATEWAY_ROUTE_ATTR = "gatewayRoute";
+	String GATEWAY_REQUEST_URL_ATTR = "requestUrl";
+
 	default boolean shouldFilter(ServerWebExchange exchange) {
 		return true;
 	}
diff --git a/src/main/java/org/springframework/cloud/gateway/GatewayHostHandlerMapping.java b/src/main/java/org/springframework/cloud/gateway/GatewayHostHandlerMapping.java
index 822a001e0..216cfdf8c 100644
--- a/src/main/java/org/springframework/cloud/gateway/GatewayHostHandlerMapping.java
+++ b/src/main/java/org/springframework/cloud/gateway/GatewayHostHandlerMapping.java
@@ -18,6 +18,8 @@ import org.springframework.web.server.WebHandler;
 
 import reactor.core.publisher.Mono;
 
+import static org.springframework.cloud.gateway.GatewayFilter.GATEWAY_ROUTE_ATTR;
+
 /**
  * @author Spencer Gibb
  */
@@ -123,7 +125,7 @@ public class GatewayHostHandlerMapping extends AbstractHandlerMapping {
 
 		if (handler instanceof RouteHolder) {
 			RouteHolder holder = (RouteHolder) handler;
-			exchange.getAttributes().put("gatewayRoute", holder.route);
+			exchange.getAttributes().put(GATEWAY_ROUTE_ATTR, holder.route);
 			return holder.webHandler;
 		}
 
diff --git a/src/main/java/org/springframework/cloud/gateway/GatewayUrlHandlerMapping.java b/src/main/java/org/springframework/cloud/gateway/GatewayUrlHandlerMapping.java
index 697b49d81..64e19cab9 100644
--- a/src/main/java/org/springframework/cloud/gateway/GatewayUrlHandlerMapping.java
+++ b/src/main/java/org/springframework/cloud/gateway/GatewayUrlHandlerMapping.java
@@ -34,7 +34,7 @@ public class GatewayUrlHandlerMapping extends AbstractUrlHandlerMapping {
 		return super.getHandler(exchange).map(o -> {
 			if (o instanceof RouteHolder) {
 				RouteHolder holder = (RouteHolder) o;
-				exchange.getAttributes().put("gatewayRoute", holder.route);
+				exchange.getAttributes().put(GatewayFilter.GATEWAY_ROUTE_ATTR, holder.route);
 				return holder.webHandler;
 			}
 			return o;
diff --git a/src/main/java/org/springframework/cloud/gateway/GatewayWebHandler.java b/src/main/java/org/springframework/cloud/gateway/GatewayWebHandler.java
index f605e244e..58a11ee5e 100644
--- a/src/main/java/org/springframework/cloud/gateway/GatewayWebHandler.java
+++ b/src/main/java/org/springframework/cloud/gateway/GatewayWebHandler.java
@@ -13,6 +13,8 @@ import reactor.core.publisher.Mono;
 import java.net.URI;
 import java.util.Optional;
 
+import static org.springframework.cloud.gateway.GatewayFilter.GATEWAY_REQUEST_URL_ATTR;
+
 /**
  * @author Spencer Gibb
  */
@@ -28,8 +30,7 @@ public class GatewayWebHandler implements WebHandler {
 
 	@Override
 	public Mono<Void> handle(ServerWebExchange exchange) {
-		//TODO: move to constant
-		Optional<URI> requestUrl = exchange.getAttribute("requestUrl");
+		Optional<URI> requestUrl = exchange.getAttribute(GATEWAY_REQUEST_URL_ATTR);
 		ServerHttpRequest request = exchange.getRequest();
 		ClientRequest<Void> clientRequest = ClientRequest
 				.method(request.getMethod(), requestUrl.get())
diff --git a/src/main/java/org/springframework/cloud/gateway/filters/RouteToUrlFilter.java b/src/main/java/org/springframework/cloud/gateway/filters/RouteToUrlFilter.java
index db8208521..4399a60d7 100644
--- a/src/main/java/org/springframework/cloud/gateway/filters/RouteToUrlFilter.java
+++ b/src/main/java/org/springframework/cloud/gateway/filters/RouteToUrlFilter.java
@@ -20,6 +20,7 @@ import reactor.core.publisher.Mono;
 public class RouteToUrlFilter implements GatewayFilter, Ordered {
 
 	private static final Log log = LogFactory.getLog(RouteToUrlFilter.class);
+	public static final int ROUTE_TO_URL_FILTER_ORDER = 500;
 
 	private final GatewayProperties properties;
 
@@ -29,23 +30,21 @@ public class RouteToUrlFilter implements GatewayFilter, Ordered {
 
 	@Override
 	public int getOrder() {
-		// TODO: move to constant
-		return 500;
+		return ROUTE_TO_URL_FILTER_ORDER;
 	}
 
 	// TODO: do we really need shouldFilter or just move the if into filter?
 	@Override
 	public boolean shouldFilter(ServerWebExchange exchange) {
-		//TODO: move to constant
-		return exchange.getAttributes().containsKey("gatewayRoute");
+		return exchange.getAttributes().containsKey(GATEWAY_ROUTE_ATTR);
 	}
 
 	@Override
 	public Mono<Void> filter(ServerWebExchange exchange, WebFilterChain chain) {
 		log.info("RouteToUrlFilter start");
-		Object gatewayRoute = exchange.getAttributes().get("gatewayRoute");
+		Object gatewayRoute = exchange.getAttributes().get(GATEWAY_ROUTE_ATTR);
 		if (!(gatewayRoute instanceof Route)) {
-			return Mono.error(new IllegalStateException("gatewayRoute" +
+			return Mono.error(new IllegalStateException(GATEWAY_ROUTE_ATTR +
 					" not an instance of " + Route.class.getSimpleName() +
 					", is " + gatewayRoute.getClass()));
 		}
@@ -54,8 +53,7 @@ public class RouteToUrlFilter implements GatewayFilter, Ordered {
 				.uri(route.getDownstreamUrl())
 				.build(true)
 				.toUri();
-		//TODO: move to constant
-		exchange.getAttributes().put("requestUrl", requestUrl);
+		exchange.getAttributes().put(GATEWAY_REQUEST_URL_ATTR, requestUrl);
 		return chain.filter(exchange);
 	}