基于MySQL的AI对话持久化简单实现——AI 超级智能体—— 3 - AI 应用开发

依赖

▼
xml
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        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-spring-boot3-starter</artifactId>
            <version>3.5.12</version>
        </dependency>
        <dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
        </dependency>

数据表

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sql
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DROP TABLE IF EXISTS `chat_message`;
CREATE TABLE IF NOT EXISTS `chat_message`
(
    `id`              bigint unsigned NOT NULL AUTO_INCREMENT COMMENT '主键ID',
    `conversation_id` varchar(64)     NOT NULL COMMENT '会话ID',
    `message_type`    varchar(20)     NOT NULL COMMENT '消息类型',
    `content`         text            NOT NULL COMMENT '消息内容',
    `metadata`        text            NOT NULL COMMENT '元数据',
    `create_time`     datetime        NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '创建时间',
    `update_time`     datetime        NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP COMMENT '更新时间',
    `is_delete`       tinyint(1)      NOT NULL DEFAULT 0 COMMENT '是否删除 0-未删除 1-已删除',
    PRIMARY KEY (`id`),
    INDEX `idx_conversation_id` (`conversation_id`)
) ENGINE = InnoDB
  DEFAULT CHARSET = utf8mb4 COMMENT ='聊天消息表';

实体类 ChatMessage

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java
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@Data
@Builder
@AllArgsConstructor
@NoArgsConstructor
@TableName(value = "`chat_message`", autoResultMap = true)
public class ChatMessage implements Serializable {

    @Serial
    @TableField(exist = false)
    private static final long serialVersionUID = 1L;

    @TableId(value = "id", type = IdType.ASSIGN_ID)
    private Long id;
    
    /**
     * 会话ID
     */
    @TableField("conversation_id")
    private String conversationId;
    
    /**
     * 消息类型
     */

    @TableField("message_type")
    private MessageType messageType;

    /**
     * 消息内容
     */
    @TableField("content")
    private String content;

    /**
     * 元数据
     */
    @TableField(value = "metadata", typeHandler = JacksonTypeHandler.class)
    private Map<String, Object> metadata;

    /**
     * 创建时间
     */
    @TableField(value = "`create_time`", fill = FieldFill.INSERT)
    private Date createTime;
    
    /**
     * 更新时间
     */
    @Version
    @TableField(value = "`update_time`", fill = FieldFill.INSERT_UPDATE)
    private Date updateTime;
    
    /**
     * 是否删除 0-未删除 1-已删除
     */
    @TableField("`is_delete`")
    @TableLogic
    private boolean isDelete;

}

ChatMessage <=> Message 转换

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java
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public class MessageConverter {

    /**
     * 将 Message 转换为 ChatMessage
     */
    public static ChatMessage toChatMessage(Message message, String conversationId) {
        return ChatMessage.builder()
                .conversationId(conversationId)
                .messageType(message.getMessageType())
                .content(message.getText())
                .metadata(message.getMetadata())
                .build();
    }

    /**
     * 将 ChatMessage 转换为 Message
     */
    public static Message toMessage(ChatMessage chatMessage) {
        MessageType messageType = chatMessage.getMessageType();
        String text = chatMessage.getContent();
        Map<String, Object> metadata = chatMessage.getMetadata();
        return switch (messageType) {
            case USER -> new UserMessage(text);
            case ASSISTANT -> new AssistantMessage(text, metadata);
            case SYSTEM -> new SystemMessage(text);
            case TOOL -> new ToolResponseMessage(List.of(), metadata);
        };
    }

}

Mybatis-Plus 相关类

▼
java
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@Mapper
public interface ChatMessageMapper extends BaseMapper<ChatMessage> {
}

@Component
public class ChatMessageRepository extends CrudRepository<ChatMessageMapper, ChatMessage> {
}

核心 ChatMemory 实现

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java
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@Component
@RequiredArgsConstructor
public class DatabaseChatMemory implements ChatMemory {

    private final ChatMessageRepository chatMessageRepository;

    @Override
    public void add(String conversationId, List<Message> messages) {
        List<ChatMessage> chatMessages = messages.stream()
                .map(message -> MessageConverter.toChatMessage(message, conversationId))
                .collect(Collectors.toList());
        
        chatMessageRepository.saveBatch(chatMessages, chatMessages.size());
    }

    @Override
    public List<Message> get(String conversationId, int lastN) {
        LambdaQueryWrapper<ChatMessage> queryWrapper = new LambdaQueryWrapper<>();
        // 查询最近的 lastN 条消息
        queryWrapper.eq(ChatMessage::getConversationId, conversationId)
                   .orderByDesc(ChatMessage::getCreateTime)
                   .last(lastN > 0, "LIMIT " + lastN);
        
        List<ChatMessage> chatMessages = chatMessageRepository.list(queryWrapper);
        
        // 按照时间顺序返回
        if (!chatMessages.isEmpty()) {
            Collections.reverse(chatMessages);
        }
        
        return chatMessages
                .stream()
                .map(MessageConverter::toMessage)
                .collect(Collectors.toList());
    }

    @Override
    public void clear(String conversationId) {
        LambdaQueryWrapper<ChatMessage> queryWrapper = new LambdaQueryWrapper<>();
        queryWrapper.eq(ChatMessage::getConversationId, conversationId);
        chatMessageRepository.remove(queryWrapper);
    }

}

使用

注入 DatabaseChatMemory

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java
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    public EcApp(ChatModel dashscopeChatModel, DatabaseChatMemory databaseChatMemory) {
        String memoryPath = System.getProperty("user.dir") + "/tmp/chat-memory";
        // ChatMemory chatMemory = new InMemoryChatMemory();
        // ChatMemory chatMemory = new FileBasedChatMemory(memoryPath);
        chatClient = ChatClient.builder(dashscopeChatModel)
                .defaultSystem(SYSTEM_PROMPT)
                .defaultAdvisors(
                        new MessageChatMemoryAdvisor(databaseChatMemory),
                        new CustomLoggerAdvisor(),
                        new ReReadingAdvisor()
                )
                .build();
    }