Use LinkedHashMap for CORS configurations in CorsGatewayFilterApplicationListener to preserve insertion order. Fixes GH-3805.

Signed-off-by: Yavor Chamov <[email protected]>

Author: yavor300

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

@@ -19,6 +19,7 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -64,7 +65,7 @@ public CorsGatewayFilterApplicationListener(GlobalCorsProperties globalCorsPrope
 	public void onApplicationEvent(RefreshRoutesResultEvent event) {
 		routeLocator.getRoutes().collectList().subscribe(routes -> {
 			// pre-populate with pre-existing global cors configurations to combine with.
-			var corsConfigurations = new HashMap<>(globalCorsProperties.getCorsConfigurations());
+			var corsConfigurations = new LinkedHashMap<>(globalCorsProperties.getCorsConfigurations());
 
 			routes.forEach(route -> {
 				var corsConfiguration = getCorsConfiguration(route);