From dadd474d214de7a39d7c025a807e4434c3584832 Mon Sep 17 00:00:00 2001
From: rstoyanchev <rossen.stoyanchev@broadcom.com>
Date: Fri, 26 Jun 2026 11:21:38 +0100
Subject: [PATCH] Update exception messages in HandshakeWebSocketService

Closes gh-37023
---
 .../socket/server/support/HandshakeWebSocketService.java      | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/server/support/HandshakeWebSocketService.java b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/server/support/HandshakeWebSocketService.java
index 9eed2bf0030..e29cb2279e4 100644
--- a/spring-webflux/src/main/java/org/springframework/web/reactive/socket/server/support/HandshakeWebSocketService.java
+++ b/spring-webflux/src/main/java/org/springframework/web/reactive/socket/server/support/HandshakeWebSocketService.java
@@ -195,12 +195,12 @@ public class HandshakeWebSocketService implements WebSocketService, Lifecycle {
 
 		if (HttpMethod.GET == method) {
 			if (!"WebSocket".equalsIgnoreCase(headers.getUpgrade())) {
-				return handleBadRequest(exchange, "Invalid 'Upgrade' header: " + headers);
+				return handleBadRequest(exchange, "Can \"Upgrade\" only to \"WebSocket\".");
 			}
 
 			List<String> connectionValue = headers.getConnection();
 			if (!connectionValue.contains("Upgrade") && !connectionValue.contains("upgrade")) {
-				return handleBadRequest(exchange, "Invalid 'Connection' header: " + headers);
+				return handleBadRequest(exchange, "\"Connection\" must be \"upgrade\".");
 			}
 
 			String key = headers.getFirst(SEC_WEBSOCKET_KEY);