Add static factory method for JacksonJsonRedisSerializer.

Introduces JacksonJsonRedisSerializer.of(Class<T>) as a static factory method for creating serializer instances, and adds RedisSerializer.json(Class<T>) as an interface-level helper method. This simplifies RedisTemplate setup code and aligns with modern Java API design conventions.

Closes #3252

Signed-off-by: Minjun Choi <mj043000@naver.com>

Author: theminjunchoi

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

@@ -50,6 +50,20 @@ public class JacksonJsonRedisSerializer<T> implements RedisSerializer<T> {
 
 	private final JacksonObjectWriter writer;
 
+	/**
+	 * Creates a new {@link JacksonJsonRedisSerializer} for the given target {@link Class}.
+	 * <p>
+	 * This is a convenience factory method equivalent to calling the constructor directly.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @param <T> the target type.
+	 * @return new instance of {@link JacksonJsonRedisSerializer}. Never {@literal null}.
+	 * @since 4.0
+	 */
+	public static <T> JacksonJsonRedisSerializer<T> of(Class<T> type) {
+		return new JacksonJsonRedisSerializer<>(type);
+	}
+
 	/**
 	 * Creates a new {@link JacksonJsonRedisSerializer} for the given target {@link Class}.
 	 *

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

@@ -65,6 +65,22 @@ static RedisSerializer<Object> json() {
 				.create(it -> it.enableSpringCacheNullValueSupport().enableUnsafeDefaultTyping());
 	}
 
+	/**
+	 * Obtain a {@link RedisSerializer} that can read and write JSON using
+	 * <a href="https://github.com/FasterXML/jackson-core">Jackson</a> for a specific type.
+	 * <p>
+	 * Unlike {@link #json()} which uses default typing, this method creates a type-safe serializer
+	 * bound to the given class.
+	 *
+	 * @param type must not be {@literal null}.
+	 * @param <T> the target type.
+	 * @return never {@literal null}.
+	 * @since 4.0
+	 */
+	static <T> RedisSerializer<T> json(Class<T> type) {
+		return new JacksonJsonRedisSerializer<>(type);
+	}
+
 	/**
 	 * Obtain a simple {@link java.lang.String} to {@code byte[]} (and back) serializer using
 	 * {@link java.nio.charset.StandardCharsets#UTF_8 UTF-8} as the default {@link java.nio.charset.Charset}.

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

@@ -0,0 +1,84 @@
+/*
+ * Copyright 2025 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 org.junit.jupiter.api.Test;
+
+import org.springframework.data.redis.Person;
+import org.springframework.data.redis.PersonObjectFactory;
+
+/**
+ * Unit tests for {@link JacksonJsonRedisSerializer}.
+ *
+ * @author Minjun Choi
+ */
+class JacksonJsonRedisSerializerUnitTests {
+
+	@Test // GH-3252
+	void ofShouldCreateSerializerForGivenType() {
+
+		JacksonJsonRedisSerializer<Person> serializer = JacksonJsonRedisSerializer.of(Person.class);
+
+		assertThat(serializer).isNotNull();
+
+		Person person = new PersonObjectFactory().instance();
+		byte[] serialized = serializer.serialize(person);
+		Person deserialized = serializer.deserialize(serialized);
+
+		assertThat(deserialized).isEqualTo(person);
+	}
+
+	@Test // GH-3252
+	void redisSerializerJsonShouldCreateSerializerForGivenType() {
+
+		RedisSerializer<Person> serializer = RedisSerializer.json(Person.class);
+
+		assertThat(serializer).isNotNull();
+		assertThat(serializer).isInstanceOf(JacksonJsonRedisSerializer.class);
+
+		Person person = new PersonObjectFactory().instance();
+		byte[] serialized = serializer.serialize(person);
+		Person deserialized = serializer.deserialize(serialized);
+
+		assertThat(deserialized).isEqualTo(person);
+	}
+
+	@Test // GH-3252
+	void serializeShouldReturnEmptyByteArrayWhenSourceIsNull() {
+
+		JacksonJsonRedisSerializer<Person> serializer = JacksonJsonRedisSerializer.of(Person.class);
+
+		assertThat(serializer.serialize(null)).isEqualTo(SerializationUtils.EMPTY_ARRAY);
+	}
+
+	@Test // GH-3252
+	void deserializeShouldReturnNullWhenSourceIsNull() {
+
+		JacksonJsonRedisSerializer<Person> serializer = JacksonJsonRedisSerializer.of(Person.class);
+
+		assertThat(serializer.deserialize(null)).isNull();
+	}
+
+	@Test // GH-3252
+	void deserializeShouldReturnNullWhenSourceIsEmptyArray() {
+
+		JacksonJsonRedisSerializer<Person> serializer = JacksonJsonRedisSerializer.of(Person.class);
+
+		assertThat(serializer.deserialize(SerializationUtils.EMPTY_ARRAY)).isNull();
+	}
+}