[Chat Memory] support redis chat memory by spring StringRedisTemplate

memory/spring-ai-model-chat-memory-redis/README.md

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+## Spring AI Redis Chat Memory
+
+This module provides a Redis chat memory implementation for Spring AI.

memory/spring-ai-model-chat-memory-redis/pom.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright 2023-2024 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.
+  -->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+		 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+		 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.ai</groupId>
+		<artifactId>spring-ai-parent</artifactId>
+		<version>1.0.0-SNAPSHOT</version>
+		<relativePath>../../pom.xml</relativePath>
+	</parent>
+
+	<artifactId>spring-ai-model-chat-memory-redis</artifactId>
+	<name>Spring AI Redis Chat Memory</name>
+	<description>Spring AI Redis Chat Memory implementation</description>
+
+	<url>https://github.com/spring-projects/spring-ai</url>
+
+	<scm>
+		<url>https://github.com/spring-projects/spring-ai</url>
+		<connection>git://github.com/spring-projects/spring-ai.git</connection>
+		<developerConnection>[email protected]:spring-projects/spring-ai.git</developerConnection>
+	</scm>
+
+	<dependencies>
+		<!-- Chat Memory APIs -->
+		<dependency>
+			<groupId>org.springframework.ai</groupId>
+			<artifactId>spring-ai-model</artifactId>
+			<version>${project.version}</version>
+		</dependency>
+		<!-- Redis Client: use Spring RedisTemplate -->
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-redis</artifactId>
+		</dependency>
+	</dependencies>
+
+</project>

memory/spring-ai-model-chat-memory-redis/src/main/java/org/springframework/ai/chat/memory/redis/RedisChatMemoryRepository.java

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+/*
+ * Copyright 2023-2025 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.ai.chat.memory.redis;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.core.type.TypeReference;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.ai.chat.memory.ChatMemoryRepository;
+import org.springframework.ai.chat.messages.AssistantMessage;
+import org.springframework.ai.chat.messages.Message;
+import org.springframework.ai.chat.messages.MessageType;
+import org.springframework.ai.chat.messages.SystemMessage;
+import org.springframework.ai.chat.messages.ToolResponseMessage;
+import org.springframework.ai.chat.messages.UserMessage;
+import org.springframework.data.redis.core.StringRedisTemplate;
+import org.springframework.util.Assert;
+
+import java.io.Serializable;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+import java.util.stream.Collectors;
+
+/**
+ * Redis(<a href="https://github.com/redis/redis">Redis</a>) Chat Memory Repository, using
+ * spring RedisTemplate.
+ *
+ * @author lambochen
+ * @see org.springframework.data.redis.core.StringRedisTemplate
+ * @see org.springframework.data.redis.core.RedisTemplate
+ * @since 1.0.0
+ */
+public class RedisChatMemoryRepository implements ChatMemoryRepository {
+
+	private static final Logger log = LoggerFactory.getLogger(RedisChatMemoryRepository.class);
+
+	private final StringRedisTemplate redisTemplate;
+
+	/**
+	 * Key prefix for Redis keys. The full key is "{keyPrefix}{conversationId}"
+	 */
+	private final String keyPrefix;
+
+	/**
+	 * ObjectMapper for serializing and deserializing {@link RedisMessage}.
+	 */
+	private final ObjectMapper objectMapper;
+
+	/**
+	 * Request timeout for Redis operations.
+	 */
+	private final long requestTimeout;
+
+	/**
+	 * Request time unit for Redis operations.
+	 */
+	private final TimeUnit requestTimeUnit;
+
+	/**
+	 * Default key prefix is blank, as the full key is "{conversationId}"
+	 */
+	private static final String DEFAULT_KEY_PREFIX = "";
+
+	/**
+	 * Default request timeout is -1, which means no timeout.
+	 */
+	private static final long DEFAULT_REQUEST_TIMEOUT = -1;
+
+	/**
+	 * Default request time unit is milliseconds.
+	 */
+	private static final TimeUnit DEFAULT_REQUEST_TIME_UNIT = TimeUnit.MILLISECONDS;
+
+	/**
+	 * Create a new {@link RedisChatMemoryRepository} instance. The key prefix is
+	 * {@link #DEFAULT_KEY_PREFIX}, as the full key is "{conversationId}"
+	 * @param redisTemplate the StringRedisTemplate instance
+	 */
+	public RedisChatMemoryRepository(StringRedisTemplate redisTemplate) {
+		this(redisTemplate, DEFAULT_KEY_PREFIX);
+	}
+
+	/**
+	 * Create a new {@link RedisChatMemoryRepository} instance. The key prefix is
+	 * {@link #DEFAULT_KEY_PREFIX}, as the full key is "{keyPrefix}{conversationId}" The
+	 * ObjectMapper is {@link #defaultObjectMapper()}.
+	 * @param redisTemplate the StringRedisTemplate instance
+	 * @param keyPrefix the key prefix for Redis keys
+	 */
+	public RedisChatMemoryRepository(StringRedisTemplate redisTemplate, String keyPrefix) {
+		this(redisTemplate, keyPrefix, defaultObjectMapper());
+	}
+
+	/**
+	 * Create a new {@link RedisChatMemoryRepository} instance.
+	 * @param redisTemplate the StringRedisTemplate instance
+	 * @param keyPrefix the key prefix for Redis keys
+	 * @param objectMapper the ObjectMapper instance, for serializing and deserializing
+	 * {@link RedisMessage}
+	 */
+	public RedisChatMemoryRepository(StringRedisTemplate redisTemplate, String keyPrefix, ObjectMapper objectMapper) {
+		this(redisTemplate, keyPrefix, objectMapper, DEFAULT_REQUEST_TIMEOUT, DEFAULT_REQUEST_TIME_UNIT);
+	}
+
+	/**
+	 * Create a new {@link RedisChatMemoryRepository} instance.
+	 * @param redisTemplate the StringRedisTemplate instance
+	 * @param keyPrefix the key prefix for Redis keys
+	 * @param objectMapper the ObjectMapper instance, for serializing and deserializing
+	 * {@link RedisMessage}
+	 * @param requestTimeout the request timeout for Redis operations
+	 * @param requestTimeUnit the request time unit for Redis operations
+	 */
+	public RedisChatMemoryRepository(StringRedisTemplate redisTemplate, String keyPrefix, ObjectMapper objectMapper,
+			long requestTimeout, TimeUnit requestTimeUnit) {
+		this.redisTemplate = redisTemplate;
+		this.keyPrefix = keyPrefix;
+		if (null == objectMapper) {
+			// default
+			this.objectMapper = defaultObjectMapper();
+		}
+		else {
+			this.objectMapper = objectMapper;
+		}
+
+		this.requestTimeout = requestTimeout;
+		this.requestTimeUnit = requestTimeUnit;
+	}
+
+	@Override
+	public List<String> findConversationIds() {
+		// FIXME: "RedisTemplate.keys(pattern)" is a low performance operation.
+		Set<String> allKeys = redisTemplate.keys("*");
+		if (null == allKeys || allKeys.isEmpty()) {
+			return List.of();
+		}
+
+		return allKeys.stream().map(this::parseConversationId).collect(Collectors.toList());
+	}
+
+	@Override
+	public List<Message> findByConversationId(String conversationId) {
+		String key = generateKey(conversationId);
+		String serializedMessages;
+		if (noRequestTimeout()) {
+			serializedMessages = redisTemplate.opsForValue().get(key);
+		}
+		else {
+			serializedMessages = redisTemplate.opsForValue().getAndExpire(key, requestTimeout, requestTimeUnit);
+		}
+
+		if (null == serializedMessages || serializedMessages.isEmpty()) {
+			return List.of();
+		}
+		return toMessages(deserialize(serializedMessages));
+	}
+
+	@Override
+	public void saveAll(String conversationId, List<Message> messages) {
+		Assert.hasText(conversationId, "conversationId cannot be null or empty");
+		Assert.notNull(messages, "messages cannot be null");
+		Assert.noNullElements(messages, "messages cannot contain null elements");
+		this.deleteByConversationId(conversationId);
+
+		List<RedisMessage> redisMessages = toRedisMessages(messages);
+		String key = generateKey(conversationId);
+		String serializedMessages = serialize(redisMessages);
+		if (noRequestTimeout()) {
+			this.redisTemplate.opsForValue().set(key, serializedMessages);
+		}
+		else {
+			this.redisTemplate.opsForValue().set(key, serializedMessages, requestTimeout, requestTimeUnit);
+		}
+	}
+
+	@Override
+	public void deleteByConversationId(String conversationId) {
+		Assert.hasText(conversationId, "conversationId cannot be null or empty");
+		this.redisTemplate.delete(generateKey(conversationId));
+	}
+
+	/**
+	 * RedisMessage is the actual model of data storage.
+	 */
+	private static class RedisMessage implements Serializable {
+
+		private static final long serialVersionUID = -6620540028783509268L;
+
+		private String type;
+
+		private String text;
+
+		public RedisMessage() {
+		}
+
+		public RedisMessage(String type, String text) {
+			this.type = type;
+			this.text = text;
+		}
+
+		public String getType() {
+			return type;
+		}
+
+		public void setType(String type) {
+			this.type = type;
+		}
+
+		public String getText() {
+			return text;
+		}
+
+		public void setText(String text) {
+			this.text = text;
+		}
+
+	}
+
+	private List<RedisMessage> toRedisMessages(List<Message> messages) {
+		return messages.stream().map(msg -> {
+			RedisMessage redisMessage = new RedisMessage();
+			redisMessage.setType(msg.getMessageType().name());
+			redisMessage.setText(msg.getText());
+			return redisMessage;
+		}).collect(Collectors.toList());
+	}
+
+	private List<Message> toMessages(List<RedisMessage> redisMessages) {
+		return redisMessages.stream().map(redisMessage -> {
+			var type = MessageType.valueOf(redisMessage.getType());
+			var text = redisMessage.getText();
+
+			return switch (type) {
+				case USER -> new UserMessage(text);
+				case ASSISTANT -> new AssistantMessage(text);
+				case SYSTEM -> new SystemMessage(text);
+				case TOOL -> new ToolResponseMessage(List.of());
+			};
+		}).collect(Collectors.toList());
+	}
+
+	private String serialize(List<RedisMessage> messages) {
+		try {
+			return objectMapper.writeValueAsString(messages);
+		}
+		catch (JsonProcessingException e) {
+			log.error("serialize messages to json failed", e);
+			throw new RuntimeException(e);
+		}
+	}
+
+	private List<RedisMessage> deserialize(String serializedMessages) {
+		try {
+			return objectMapper.readValue(serializedMessages, new TypeReference<List<RedisMessage>>() {
+			});
+		}
+		catch (JsonProcessingException e) {
+			log.error("deserialize messages from json failed", e);
+			throw new RuntimeException(e);
+		}
+	}
+
+	private static ObjectMapper defaultObjectMapper() {
+		return new ObjectMapper();
+	}
+
+	/**
+	 * The full key is "{keyPrefix}{conversationId}"
+	 * @param conversationId conversation id
+	 * @return the full key
+	 */
+	private String generateKey(String conversationId) {
+		if (null == keyPrefix || keyPrefix.isEmpty()) {
+			return conversationId;
+		}
+
+		return keyPrefix + conversationId;
+	}
+
+	/**
+	 * Parse conversation id from the full key.
+	 * @param key the full key
+	 * @return conversation id
+	 */
+	private String parseConversationId(String key) {
+		if (null == keyPrefix || keyPrefix.isEmpty()) {
+			return key;
+		}
+
+		return key.replaceFirst(keyPrefix, "");
+	}
+
+	/**
+	 * Check if there is no request timeout.
+	 * @return true if there is no request timeout
+	 */
+	private boolean noRequestTimeout() {
+		return DEFAULT_REQUEST_TIMEOUT == requestTimeout;
+	}
+
+}

memory/spring-ai-model-chat-memory-redis/src/main/java/org/springframework/ai/chat/memory/redis/package-info.java

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+/*
+ * Copyright 2023-2025 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.ai.chat.memory.redis;