使用若依后端架构 编写一个1对1单聊，可以查询历史聊天记录

以下是一个使用若依后端架构编写的1对1单聊的示例代码：

1. 首先，我们需要创建一个聊天室的数据模型：

@Entity
public class ChatRoom {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @OneToOne
    private User user1;

    @OneToOne
    private User user2;

    @OneToMany(mappedBy = "chatRoom", cascade = CascadeType.ALL)
    private List<ChatMessage> messages = new ArrayList<>();

    // getters and setters
}

2. 接下来，我们需要创建一个聊天消息的数据模型：

@Entity
public class ChatMessage {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    private String message;

    @ManyToOne
    private User sender;

    @ManyToOne
    private User receiver;

    @ManyToOne
    private ChatRoom chatRoom;

    private LocalDateTime timestamp;

    // getters and setters
}

3. 然后，我们需要创建一个服务类来处理聊天室和聊天消息的逻辑：

@Service
public class ChatService {

    @Autowired
    ChatRoomRepository chatRoomRepository;

    @Autowired
    ChatMessageRepository chatMessageRepository;

    public ChatRoom createChatRoom(User user1, User user2) {
        ChatRoom chatRoom = new ChatRoom();
        chatRoom.setUser1(user1);
        chatRoom.setUser2(user2);
        return chatRoomRepository.save(chatRoom);
    }

    public ChatMessage sendMessage(User sender, User receiver, ChatRoom chatRoom, String message) {
        ChatMessage chatMessage = new ChatMessage();
        chatMessage.setSender(sender);
        chatMessage.setReceiver(receiver);
        chatMessage.setChatRoom(chatRoom);
        chatMessage.setMessage(message);
        chatMessage.setTimestamp(LocalDateTime.now());
        return chatMessageRepository.save(chatMessage);
    }

    public List<ChatMessage> getChatHistory(ChatRoom chatRoom) {
        return chatMessageRepository.findByChatRoomOrderByTimestamp(chatRoom);
    }
}

4. 最后，我们需要创建一个控制器来处理聊天室和聊天消息的请求：

@RestController
@RequestMapping("/chat")
public class ChatController {

    @Autowired
    ChatService chatService;

    @GetMapping("/history/{chatRoomId}")
    public List<ChatMessage> getChatHistory(@PathVariable Long chatRoomId) {
        ChatRoom chatRoom = chatService.getChatRoomById(chatRoomId);
        return chatService.getChatHistory(chatRoom);
    }

    @PostMapping("/{chatRoomId}")
    public ChatMessage sendMessage(@PathVariable Long chatRoomId, @RequestBody String message) {
        User sender = getCurrentUser();
        ChatRoom chatRoom = chatService.getChatRoomById(chatRoomId);
        User receiver = chatRoom.getReceiver(sender);
        return chatService.sendMessage(sender, receiver, chatRoom, message);
    }

    private User getCurrentUser() {
        // 获取当前用户的逻辑
    }
}

这样，我们就可以使用若依后端架构来实现一个1对1单聊，并且可以查询历史聊天记录了。