From 8396c071af928b5b7e9f74525b5c1e474137eda6 Mon Sep 17 00:00:00 2001
From: Brian Clozel <brian.clozel@broadcom.com>
Date: Tue, 10 Feb 2026 09:58:25 +0100
Subject: [PATCH] Fix wildcard MIME type support in messaging converters

Prior to this commit, the "application/*+json" wildcard MIME type was
added to the list of supported MIME types in the JSON messaging
converter. This change wasn't fully reflected in the
`AbstractMessageConverter`, because only strict matching of type and
subtybe were considered.

This commit updates the `AbstractMessageConverter` to not only check the
type and subtype, but also check whether the supported MIME type
includes the one given as a parameter.

Fixes gh-36285
---
 .../converter/AbstractMessageConverter.java   |  2 +-
 .../MappingJackson2MessageConverterTests.java | 20 +++++++++++++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/spring-messaging/src/main/java/org/springframework/messaging/converter/AbstractMessageConverter.java b/spring-messaging/src/main/java/org/springframework/messaging/converter/AbstractMessageConverter.java
index 381a9326528..f372ab45638 100644
--- a/spring-messaging/src/main/java/org/springframework/messaging/converter/AbstractMessageConverter.java
+++ b/spring-messaging/src/main/java/org/springframework/messaging/converter/AbstractMessageConverter.java
@@ -242,7 +242,7 @@ public abstract class AbstractMessageConverter implements SmartMessageConverter
 			return !isStrictContentTypeMatch();
 		}
 		for (MimeType current : getSupportedMimeTypes()) {
-			if (current.getType().equals(mimeType.getType()) && current.getSubtype().equals(mimeType.getSubtype())) {
+			if (current.includes(mimeType)) {
 				return true;
 			}
 		}
diff --git a/spring-messaging/src/test/java/org/springframework/messaging/converter/MappingJackson2MessageConverterTests.java b/spring-messaging/src/test/java/org/springframework/messaging/converter/MappingJackson2MessageConverterTests.java
index 85c6bbba659..e3168f49f93 100644
--- a/spring-messaging/src/test/java/org/springframework/messaging/converter/MappingJackson2MessageConverterTests.java
+++ b/spring-messaging/src/test/java/org/springframework/messaging/converter/MappingJackson2MessageConverterTests.java
@@ -54,7 +54,7 @@ class MappingJackson2MessageConverterTests {
 	}
 
 	@Test  // SPR-12724
-	public void mimetypeParametrizedConstructor() {
+	void mimetypeParametrizedConstructor() {
 		MimeType mimetype = new MimeType("application", "xml", StandardCharsets.UTF_8);
 		MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter(mimetype);
 		assertThat(converter.getSupportedMimeTypes()).contains(mimetype);
@@ -63,7 +63,7 @@ class MappingJackson2MessageConverterTests {
 	}
 
 	@Test  // SPR-12724
-	public void mimetypesParametrizedConstructor() {
+	void mimetypesParametrizedConstructor() {
 		MimeType jsonMimetype = new MimeType("application", "json", StandardCharsets.UTF_8);
 		MimeType xmlMimetype = new MimeType("application", "xml", StandardCharsets.UTF_8);
 		MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter(jsonMimetype, xmlMimetype);
@@ -72,6 +72,22 @@ class MappingJackson2MessageConverterTests {
 				.isEnabled(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES)).isFalse();
 	}
 
+	@Test
+	void supportJsonMimeType() {
+		MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
+		Message<String> message = MessageBuilder.withPayload("foo")
+				.setHeader(MessageHeaders.CONTENT_TYPE, "application/json").build();
+		assertThat(converter.supportsMimeType(message.getHeaders())).isTrue();
+	}
+
+	@Test
+	void supportVendorJsonMimeTypes() {
+		MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();
+		Message<String> message = MessageBuilder.withPayload("foo")
+				.setHeader(MessageHeaders.CONTENT_TYPE, "application/vnd.springframework.type+json").build();
+		assertThat(converter.supportsMimeType(message.getHeaders())).isTrue();
+	}
+
 	@Test
 	void fromMessage() {
 		MappingJackson2MessageConverter converter = new MappingJackson2MessageConverter();