From c1876326f2fa1e82a6adc30a720c4604c376c1cb Mon Sep 17 00:00:00 2001
From: dragonfsky <dragonfsky@gmail.com>
Date: Mon, 4 May 2026 20:06:25 +0800
Subject: [PATCH] Handle WebSocket messages after MVC session closed

Ignore text messages received after the MVC WebSocket session state has already been removed during connection close.

Closes gh-1449

Signed-off-by: dragonfsky <dragonfsky@gmail.com>
---
 .../server/webmvc/GraphQlWebSocketHandler.java  |  5 ++++-
 .../webmvc/GraphQlWebSocketHandlerTests.java    | 17 +++++++++++++++++
 2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/spring-graphql/src/main/java/org/springframework/graphql/server/webmvc/GraphQlWebSocketHandler.java b/spring-graphql/src/main/java/org/springframework/graphql/server/webmvc/GraphQlWebSocketHandler.java
index 6faeda65..0e0eff7c 100644
--- a/spring-graphql/src/main/java/org/springframework/graphql/server/webmvc/GraphQlWebSocketHandler.java
+++ b/spring-graphql/src/main/java/org/springframework/graphql/server/webmvc/GraphQlWebSocketHandler.java
@@ -245,10 +245,13 @@ protected void handleTextMessage(WebSocketSession session, TextMessage webSocket
 	}
 
 	private void handleInternal(WebSocketSession session, TextMessage webSocketMessage) throws IOException {
+		SessionState state = this.sessionInfoMap.get(session.getId());
+		if (state == null) {
+			return;
+		}
 		GraphQlWebSocketMessage message = decode(webSocketMessage);
 		String id = message.getId();
 		Map<String, Object> payload = message.getPayload();
-		SessionState state = getSessionInfo(session);
 		switch (message.resolvedType()) {
 			case SUBSCRIBE -> {
 				if (state.getConnectionInitPayload() == null) {
diff --git a/spring-graphql/src/test/java/org/springframework/graphql/server/webmvc/GraphQlWebSocketHandlerTests.java b/spring-graphql/src/test/java/org/springframework/graphql/server/webmvc/GraphQlWebSocketHandlerTests.java
index 40509148..ec4bd254 100644
--- a/spring-graphql/src/test/java/org/springframework/graphql/server/webmvc/GraphQlWebSocketHandlerTests.java
+++ b/spring-graphql/src/test/java/org/springframework/graphql/server/webmvc/GraphQlWebSocketHandlerTests.java
@@ -71,6 +71,7 @@
 
 import static org.assertj.core.api.Assertions.as;
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatNoException;
 import static org.mockito.Mockito.mock;
 import static org.springframework.graphql.server.support.GraphQlWebSocketMessageType.CONNECTION_ACK;
 import static org.springframework.graphql.server.support.GraphQlWebSocketMessageType.PING;
@@ -273,6 +274,22 @@ public void handleConnectionClosed(WebSocketSessionInfo info, int status, Map<St
 		assertThat(called).isTrue();
 	}
 
+	@Test
+	void messageAfterConnectionClosed() throws Exception {
+		handle(this.handler, new TextMessage("{\"type\":\"connection_init\"}"));
+
+		StepVerifier.create(this.session.getOutput())
+				.consumeNextWith((message) -> assertMessageType(message, GraphQlWebSocketMessageType.CONNECTION_ACK))
+				.then(this.session::close)
+				.expectComplete()
+				.verify(TIMEOUT);
+
+		this.handler.afterConnectionClosed(this.session, CloseStatus.NORMAL);
+
+		assertThatNoException().isThrownBy(() ->
+				this.handler.handleTextMessage(this.session, new TextMessage("{\"type\":\"ping\"}")));
+	}
+
 	@Test
 	void connectionInitRejected() throws Exception {