Refine default typing configuration for RedisMessageConverters

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-redis</artifactId>
-	<version>4.1.0-SNAPSHOT</version>
+	<version>4.1.0-GH-3357-SNAPSHOT</version>
 
 	<name>Spring Data Redis</name>
 	<description>Spring Data module for Redis</description>

src/main/java/org/springframework/data/redis/serializer/DefaultRedisMessageConverters.java

@@ -114,11 +114,6 @@ public RedisMessageConverters.Builder addCustomConverter(MessageConverter conver
 			return this;
 		}
 
-		public boolean hasConfiguration() {
-			return this.defaultMimeType != null || !this.registerDefaults || this.stringMessageConverter != null
-					|| customConverters.isEmpty();
-		}
-
 		@Override
 		public RedisMessageConverters build() {
 
@@ -148,7 +143,8 @@ private List<MessageConverter> getDefaultConverters() {
 						.add(new SerializerMessageConverter(GenericJacksonJsonRedisSerializer.builder().build(), JSON_MIME_TYPES));
 			} else if (JACKSON_2_PRESENT) {
 				defaultConverters
-						.add(new SerializerMessageConverter(new GenericJackson2JsonRedisSerializer(), JSON_MIME_TYPES));
+						.add(new SerializerMessageConverter(
+								GenericJackson2JsonRedisSerializer.builder().defaultTyping(false).build(), JSON_MIME_TYPES));
 			}
 			if (GSON_PRESENT) {
 				defaultConverters.add(new GsonMessageConverter());

src/test/java/org/springframework/data/redis/serializer/RedisMessageConvertersUnitTests.java

@@ -0,0 +1,95 @@
+/*
+ * Copyright 2026-present the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.redis.serializer;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageHeaders;
+import org.springframework.messaging.converter.MessageConverter;
+import org.springframework.messaging.support.MessageBuilder;
+
+/**
+ * Unit tests for {@link RedisMessageConverters}.
+ *
+ * @author Mark Paluch
+ */
+class RedisMessageConvertersUnitTests {
+
+	@Test // GH-3357
+	void serializesObjectToJson() {
+
+		MessageConverter messageConverter = RedisMessageConverters.createMessageConverter();
+
+		Person person = new Person();
+		person.setName("Walter");
+		MessageHeaders messageHeaders = new MessageHeaders(Map.of(MessageHeaders.CONTENT_TYPE, "application/json"));
+		Message<?> message = messageConverter.toMessage(person, messageHeaders);
+
+		String json = new String((byte[]) message.getPayload());
+		assertThat(json).contains("name", "Walter").doesNotContain("class");
+	}
+
+	@Test // GH-3357
+	void deserializesJsonToObject() {
+
+		MessageConverter messageConverter = RedisMessageConverters.createMessageConverter();
+
+		String json = "{\"@class\":\"org.springframework.data.redis.serializer.RedisMessageConvertersUnitTests$Hey\",\"name\":\"Walter\"}";
+		MessageHeaders messageHeaders = new MessageHeaders(Map.of(MessageHeaders.CONTENT_TYPE, "application/json"));
+		Message<byte[]> message = MessageBuilder.createMessage(json.getBytes(), messageHeaders);
+
+		assertThat(messageConverter.fromMessage(message, Object.class)).isInstanceOf(Map.class);
+		assertThat(messageConverter.fromMessage(message, Person.class)).isInstanceOf(Person.class);
+	}
+
+	static class Person {
+
+		String name;
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+	}
+
+	static class Hey {
+
+		String name;
+
+		public Hey() {
+			throw new RuntimeException("nope");
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+	}
+
+}