feat:【站内信】

backend/src/main/java/com/openisle/config/SecurityConfig.java

@@ -92,7 +92,7 @@ public class SecurityConfig {
         cfg.setAllowedHeaders(List.of("*"));
         cfg.setAllowCredentials(true);
         UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
-        source.registerCorsConfiguration("/api/**", cfg);
+        source.registerCorsConfiguration("/**", cfg);
         return source;
     }
 
@@ -104,6 +104,7 @@ public class SecurityConfig {
             .exceptionHandling(eh -> eh.accessDeniedHandler(customAccessDeniedHandler))
             .authorizeHttpRequests(auth -> auth
                     .requestMatchers(HttpMethod.OPTIONS, "/**").permitAll()
+                    .requestMatchers("/ws/**").permitAll()
                     .requestMatchers(HttpMethod.POST, "/api/auth/**").permitAll()
                     .requestMatchers(HttpMethod.GET, "/api/posts/**").permitAll()
                     .requestMatchers(HttpMethod.GET, "/api/comments/**").permitAll()
@@ -172,7 +173,7 @@ public class SecurityConfig {
                         response.getWriter().write("{\"error\": \"Invalid or expired token\"}");
                         return;
                     }
-                } else if (!uri.startsWith("/api/auth") && !publicGet) {
+                } else if (!uri.startsWith("/api/auth") && !publicGet && !uri.startsWith("/ws")) {
                     response.setStatus(HttpServletResponse.SC_UNAUTHORIZED);
                     response.setContentType("application/json");
                     response.getWriter().write("{\"error\": \"Missing token\"}");

backend/src/main/java/com/openisle/config/WebSocketConfig.java

@@ -0,0 +1,79 @@
+package com.openisle.config;
+
+import com.openisle.service.JwtService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.messaging.simp.config.ChannelRegistration;
+import org.springframework.messaging.simp.config.MessageBrokerRegistry;
+import org.springframework.messaging.simp.stomp.StompCommand;
+import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
+import org.springframework.messaging.support.ChannelInterceptor;
+import org.springframework.messaging.support.MessageHeaderAccessor;
+import org.springframework.security.authentication.UsernamePasswordAuthenticationToken;
+import org.springframework.security.core.Authentication;
+import org.springframework.security.core.userdetails.UserDetailsService;
+import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
+import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
+import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;
+
+@Configuration
+@EnableWebSocketMessageBroker
+@RequiredArgsConstructor
+public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
+    
+    private final JwtService jwtService;
+    private final UserDetailsService userDetailsService;
+
+    @Override
+    public void configureMessageBroker(MessageBrokerRegistry config) {
+        // Enable a simple memory-based message broker to carry the messages back to the client on destinations prefixed with "/topic" and "/queue"
+        config.enableSimpleBroker("/topic", "/queue");
+        // Set user destination prefix for personal messages
+        config.setUserDestinationPrefix("/user");
+        // Designates the "/app" prefix for messages that are bound for @MessageMapping-annotated methods.
+        config.setApplicationDestinationPrefixes("/app");
+    }
+
+    @Override
+    public void registerStompEndpoints(StompEndpointRegistry registry) {
+        // Registers the "/ws" endpoint, enabling SockJS fallback options so that alternate transports may be used if WebSocket is not available.
+        registry.addEndpoint("/ws").setAllowedOriginPatterns("*").withSockJS();
+    }
+
+    @Override
+    public void configureClientInboundChannel(ChannelRegistration registration) {
+        registration.interceptors(new ChannelInterceptor() {
+            @Override
+            public Message<?> preSend(Message<?> message, MessageChannel channel) {
+                StompHeaderAccessor accessor = MessageHeaderAccessor.getAccessor(message, StompHeaderAccessor.class);
+                
+                if (StompCommand.CONNECT.equals(accessor.getCommand())) {
+                    System.out.println("WebSocket CONNECT command received");
+                    String authHeader = accessor.getFirstNativeHeader("Authorization");
+                    System.out.println("Authorization header: " + (authHeader != null ? "present" : "missing"));
+                    
+                    if (authHeader != null && authHeader.startsWith("Bearer ")) {
+                        String token = authHeader.substring(7);
+                        try {
+                            String username = jwtService.validateAndGetSubject(token);
+                            System.out.println("JWT validated for user: " + username);
+                            var userDetails = userDetailsService.loadUserByUsername(username);
+                            Authentication auth = new UsernamePasswordAuthenticationToken(
+                                userDetails, null, userDetails.getAuthorities());
+                            accessor.setUser(auth);
+                            System.out.println("WebSocket user set: " + username);
+                        } catch (Exception e) {
+                            System.err.println("JWT validation failed: " + e.getMessage());
+                        }
+                    }
+                } else if (StompCommand.SUBSCRIBE.equals(accessor.getCommand())) {
+                    System.out.println("WebSocket SUBSCRIBE to: " + accessor.getDestination());
+                    System.out.println("WebSocket user during subscribe: " + (accessor.getUser() != null ? accessor.getUser().getName() : "null"));
+                }
+                return message;
+            }
+        });
+    }
+}

backend/src/main/java/com/openisle/controller/MessageController.java

@@ -0,0 +1,117 @@
+package com.openisle.controller;
+
+import com.openisle.dto.ConversationDetailDto;
+import com.openisle.dto.ConversationDto;
+import com.openisle.dto.CreateConversationRequest;
+import com.openisle.dto.CreateConversationResponse;
+import com.openisle.dto.MessageDto;
+import com.openisle.dto.UserSummaryDto;
+import com.openisle.model.Message;
+import com.openisle.model.MessageConversation;
+import com.openisle.model.User;
+import com.openisle.repository.UserRepository;
+import com.openisle.service.MessageService;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.PageRequest;
+import org.springframework.data.domain.Pageable;
+import org.springframework.data.domain.Sort;
+import org.springframework.http.ResponseEntity;
+import org.springframework.security.core.Authentication;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/api/messages")
+@RequiredArgsConstructor
+public class MessageController {
+
+    private final MessageService messageService;
+    private final UserRepository userRepository;
+
+    // This is a placeholder for getting the current user's ID
+    private Long getCurrentUserId(Authentication auth) {
+        User user = userRepository.findByUsername(auth.getName()).orElseThrow(() -> new IllegalArgumentException("Sender not found"));
+        // In a real application, you would get this from the Authentication object
+        return user.getId();
+    }
+
+    @GetMapping("/conversations")
+    public ResponseEntity<List<ConversationDto>> getConversations(Authentication auth) {
+        List<ConversationDto> conversations = messageService.getConversations(getCurrentUserId(auth));
+        return ResponseEntity.ok(conversations);
+    }
+
+    @GetMapping("/conversations/{conversationId}")
+    public ResponseEntity<ConversationDetailDto> getMessages(@PathVariable Long conversationId,
+                                                               @RequestParam(defaultValue = "0") int page,
+                                                               @RequestParam(defaultValue = "20") int size,
+                                                               Authentication auth) {
+        Pageable pageable = PageRequest.of(page, size, Sort.by("createdAt").descending());
+        ConversationDetailDto conversationDetails = messageService.getConversationDetails(conversationId, getCurrentUserId(auth), pageable);
+        return ResponseEntity.ok(conversationDetails);
+    }
+
+    @PostMapping
+    public ResponseEntity<MessageDto> sendMessage(@RequestBody MessageRequest req, Authentication auth) {
+        Message message = messageService.sendMessage(getCurrentUserId(auth), req.getRecipientId(), req.getContent());
+        return ResponseEntity.ok(toDto(message));
+    }
+
+    @PostMapping("/conversations/{conversationId}/read")
+    public ResponseEntity<Void> markAsRead(@PathVariable Long conversationId, Authentication auth) {
+        messageService.markConversationAsRead(conversationId, getCurrentUserId(auth));
+        return ResponseEntity.ok().build();
+    }
+
+    @PostMapping("/conversations")
+    public ResponseEntity<CreateConversationResponse> findOrCreateConversation(@RequestBody CreateConversationRequest req, Authentication auth) {
+        MessageConversation conversation = messageService.findOrCreateConversation(getCurrentUserId(auth), req.getRecipientId());
+        return ResponseEntity.ok(new CreateConversationResponse(conversation.getId()));
+    }
+
+    private MessageDto toDto(Message message) {
+        MessageDto dto = new MessageDto();
+        dto.setId(message.getId());
+        dto.setContent(message.getContent());
+        dto.setCreatedAt(message.getCreatedAt());
+
+        dto.setConversationId(message.getConversation().getId());
+
+        UserSummaryDto senderDto = new UserSummaryDto();
+        senderDto.setId(message.getSender().getId());
+        senderDto.setUsername(message.getSender().getUsername());
+        senderDto.setAvatar(message.getSender().getAvatar());
+        dto.setSender(senderDto);
+
+        return dto;
+    }
+
+    @GetMapping("/unread-count")
+    public ResponseEntity<Long> getUnreadCount(Authentication auth) {
+        return ResponseEntity.ok(messageService.getUnreadMessageCount(getCurrentUserId(auth)));
+    }
+
+    // A simple request DTO
+    static class MessageRequest {
+        private Long recipientId;
+        private String content;
+
+        public Long getRecipientId() {
+            return recipientId;
+        }
+
+        public void setRecipientId(Long recipientId) {
+            this.recipientId = recipientId;
+        }
+
+        public String getContent() {
+            return content;
+        }
+
+        public void setContent(String content) {
+            this.content = content;
+        }
+    }
+}

backend/src/main/java/com/openisle/dto/ConversationDetailDto.java

@@ -0,0 +1,13 @@
+package com.openisle.dto;
+
+import lombok.Data;
+import org.springframework.data.domain.Page;
+
+import java.util.List;
+
+@Data
+public class ConversationDetailDto {
+    private Long id;
+    private List<UserSummaryDto> participants;
+    private Page<MessageDto> messages;
+}

backend/src/main/java/com/openisle/dto/ConversationDto.java

@@ -0,0 +1,17 @@
+package com.openisle.dto;
+
+import lombok.Getter;
+import lombok.Setter;
+
+import java.time.LocalDateTime;
+import java.util.List;
+
+@Getter
+@Setter
+public class ConversationDto {
+    private Long id;
+    private MessageDto lastMessage;
+    private List<UserSummaryDto> participants;
+    private LocalDateTime createdAt;
+    private long unreadCount;
+}

backend/src/main/java/com/openisle/dto/CreateConversationRequest.java

@@ -0,0 +1,8 @@
+package com.openisle.dto;
+
+import lombok.Data;
+
+@Data
+public class CreateConversationRequest {
+    private Long recipientId;
+}

backend/src/main/java/com/openisle/dto/CreateConversationResponse.java

@@ -0,0 +1,12 @@
+package com.openisle.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class CreateConversationResponse {
+    private Long conversationId;
+}

backend/src/main/java/com/openisle/dto/MessageDto.java

@@ -0,0 +1,13 @@
+package com.openisle.dto;
+
+import lombok.Data;
+import java.time.LocalDateTime;
+
+@Data
+public class MessageDto {
+    private Long id;
+    private String content;
+    private UserSummaryDto sender;
+    private Long conversationId;
+    private LocalDateTime createdAt;
+}

backend/src/main/java/com/openisle/dto/UserSummaryDto.java

@@ -0,0 +1,10 @@
+package com.openisle.dto;
+
+import lombok.Data;
+
+@Data
+public class UserSummaryDto {
+    private Long id;
+    private String username;
+    private String avatar;
+}

backend/src/main/java/com/openisle/model/Message.java

@@ -0,0 +1,35 @@
+package com.openisle.model;
+
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.hibernate.annotations.CreationTimestamp;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@Setter
+@NoArgsConstructor
+@Table(name = "messages")
+public class Message {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(optional = false, fetch = FetchType.LAZY)
+    @JoinColumn(name = "conversation_id")
+    private MessageConversation conversation;
+
+    @ManyToOne(optional = false, fetch = FetchType.LAZY)
+    @JoinColumn(name = "sender_id")
+    private User sender;
+
+    @Column(nullable = false, columnDefinition = "TEXT")
+    private String content;
+
+    @CreationTimestamp
+    @Column(nullable = false, updatable = false)
+    private LocalDateTime createdAt;
+}

backend/src/main/java/com/openisle/model/MessageConversation.java

@@ -0,0 +1,36 @@
+package com.openisle.model;
+
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import org.hibernate.annotations.CreationTimestamp;
+
+import java.time.LocalDateTime;
+import java.util.HashSet;
+import java.util.Set;
+
+@Entity
+@Getter
+@Setter
+@NoArgsConstructor
+@Table(name = "message_conversations")
+public class MessageConversation {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @CreationTimestamp
+    @Column(nullable = false, updatable = false)
+    private LocalDateTime createdAt;
+
+    @OneToOne(fetch = FetchType.LAZY)
+    @JoinColumn(name = "last_message_id")
+    private Message lastMessage;
+
+    @OneToMany(mappedBy = "conversation", cascade = CascadeType.ALL, orphanRemoval = true)
+    private Set<MessageParticipant> participants = new HashSet<>();
+
+    @OneToMany(mappedBy = "conversation", cascade = CascadeType.ALL, orphanRemoval = true)
+    private Set<Message> messages = new HashSet<>();
+}

backend/src/main/java/com/openisle/model/MessageParticipant.java

@@ -0,0 +1,30 @@
+package com.openisle.model;
+
+import jakarta.persistence.*;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+
+import java.time.LocalDateTime;
+
+@Entity
+@Getter
+@Setter
+@NoArgsConstructor
+@Table(name = "message_participants")
+public class MessageParticipant {
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private Long id;
+
+    @ManyToOne(optional = false, fetch = FetchType.LAZY)
+    @JoinColumn(name = "conversation_id")
+    private MessageConversation conversation;
+
+    @ManyToOne(optional = false, fetch = FetchType.LAZY)
+    @JoinColumn(name = "user_id")
+    private User user;
+
+    @Column
+    private LocalDateTime lastReadAt;
+}

backend/src/main/java/com/openisle/repository/MessageConversationRepository.java

@@ -0,0 +1,31 @@
+package com.openisle.repository;
+
+import com.openisle.model.MessageConversation;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import com.openisle.model.User;
+import java.util.List;
+
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+
+import java.util.Optional;
+import com.openisle.model.User;
+import java.util.List;
+
+@Repository
+public interface MessageConversationRepository extends JpaRepository<MessageConversation, Long> {
+    @Query("SELECT c FROM MessageConversation c JOIN c.participants p1 JOIN c.participants p2 WHERE p1.user = :user1 AND p2.user = :user2")
+    Optional<MessageConversation> findConversationByUsers(@Param("user1") User user1, @Param("user2") User user2);
+    
+    @Query("SELECT DISTINCT c FROM MessageConversation c " +
+           "JOIN c.participants p " +
+           "LEFT JOIN FETCH c.lastMessage lm " +
+           "LEFT JOIN FETCH lm.sender " +
+           "LEFT JOIN FETCH c.participants cp " +
+           "LEFT JOIN FETCH cp.user " +
+           "WHERE p.user.id = :userId " +
+           "ORDER BY COALESCE(lm.createdAt, c.createdAt) DESC")
+    List<MessageConversation> findConversationsByUserIdOrderByLastMessageDesc(@Param("userId") Long userId);
+}

backend/src/main/java/com/openisle/repository/MessageParticipantRepository.java

@@ -0,0 +1,14 @@
+package com.openisle.repository;
+
+import com.openisle.model.MessageParticipant;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+import java.util.Optional;
+
+@Repository
+public interface MessageParticipantRepository extends JpaRepository<MessageParticipant, Long> {
+    Optional<MessageParticipant> findByConversationIdAndUserId(Long conversationId, Long userId);
+    List<MessageParticipant> findByUserId(Long userId);
+}

backend/src/main/java/com/openisle/repository/MessageRepository.java

@@ -0,0 +1,21 @@
+package com.openisle.repository;
+
+import com.openisle.model.Message;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.stereotype.Repository;
+
+import java.util.List;
+
+@Repository
+public interface MessageRepository extends JpaRepository<Message, Long> {
+    List<Message> findByConversationIdOrderByCreatedAtAsc(Long conversationId);
+
+    Page<Message> findByConversationId(Long conversationId, Pageable pageable);
+
+    long countByConversationIdAndCreatedAtAfter(Long conversationId, java.time.LocalDateTime createdAt);
+    
+    // 只计算不是指定用户发送的消息（即别人发给当前用户的消息）
+    long countByConversationIdAndCreatedAtAfterAndSenderIdNot(Long conversationId, java.time.LocalDateTime createdAt, Long senderId);
+}

backend/src/main/java/com/openisle/service/MessageService.java

@@ -0,0 +1,217 @@
+package com.openisle.service;
+
+import com.openisle.model.Message;
+import com.openisle.model.MessageConversation;
+import com.openisle.model.MessageParticipant;
+import com.openisle.model.User;
+import com.openisle.repository.MessageConversationRepository;
+import com.openisle.repository.MessageParticipantRepository;
+import com.openisle.repository.MessageRepository;
+import com.openisle.repository.UserRepository;
+import com.openisle.dto.ConversationDetailDto;
+import com.openisle.dto.ConversationDto;
+import com.openisle.dto.MessageDto;
+import com.openisle.dto.UserSummaryDto;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.data.domain.Page;
+import org.springframework.data.domain.Pageable;
+import org.springframework.messaging.simp.SimpMessagingTemplate;
+import org.springframework.stereotype.Service;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.stream.Collectors;
+
+@Service
+@RequiredArgsConstructor
+@Slf4j
+public class MessageService {
+
+    private final MessageRepository messageRepository;
+    private final MessageConversationRepository conversationRepository;
+    private final MessageParticipantRepository participantRepository;
+    private final UserRepository userRepository;
+    private final SimpMessagingTemplate messagingTemplate;
+
+    @Transactional
+    public Message sendMessage(Long senderId, Long recipientId, String content) {
+        log.info("Attempting to send message from user {} to user {}", senderId, recipientId);
+        User sender = userRepository.findById(senderId)
+                .orElseThrow(() -> new IllegalArgumentException("Sender not found"));
+        User recipient = userRepository.findById(recipientId)
+                .orElseThrow(() -> new IllegalArgumentException("Recipient not found"));
+
+        log.info("Finding or creating conversation for users {} and {}", sender.getUsername(), recipient.getUsername());
+        MessageConversation conversation = findOrCreateConversation(sender, recipient);
+        log.info("Conversation found or created with ID: {}", conversation.getId());
+
+        Message message = new Message();
+        message.setConversation(conversation);
+        message.setSender(sender);
+        message.setContent(content);
+        message = messageRepository.save(message);
+        log.info("Message saved with ID: {}", message.getId());
+
+        conversation.setLastMessage(message);
+        conversationRepository.save(conversation);
+        log.info("Conversation {} updated with last message ID {}", conversation.getId(), message.getId());
+
+        // Broadcast the new message to subscribed clients
+        MessageDto messageDto = toDto(message);
+        String conversationDestination = "/topic/conversation/" + conversation.getId();
+        messagingTemplate.convertAndSend(conversationDestination, messageDto);
+        log.info("Message {} broadcasted to destination: {}", message.getId(), conversationDestination);
+
+        // Also notify the recipient on their personal channel to update the conversation list
+        String userDestination = "/topic/user/" + recipient.getId() + "/messages";
+        messagingTemplate.convertAndSend(userDestination, messageDto);
+        log.info("Message {} notification sent to destination: {}", message.getId(), userDestination);
+
+        // Notify recipient of new unread count
+        long unreadCount = getUnreadMessageCount(recipientId);
+        log.info("Calculating unread count for user {}: {}", recipientId, unreadCount);
+        
+        // Send using username instead of user ID for WebSocket routing
+        String recipientUsername = recipient.getUsername();
+        messagingTemplate.convertAndSendToUser(recipientUsername, "/queue/unread-count", unreadCount);
+        log.info("Sent unread count {} to user {} (username: {}) via WebSocket destination: /user/{}/queue/unread-count",
+                unreadCount, recipientId, recipientUsername, recipientUsername);
+
+        return message;
+    }
+
+    private MessageDto toDto(Message message) {
+        MessageDto dto = new MessageDto();
+        dto.setId(message.getId());
+        dto.setContent(message.getContent());
+        dto.setConversationId(message.getConversation().getId());
+        dto.setCreatedAt(message.getCreatedAt());
+
+        UserSummaryDto userSummaryDto = new UserSummaryDto();
+        userSummaryDto.setId(message.getSender().getId());
+        userSummaryDto.setUsername(message.getSender().getUsername());
+        userSummaryDto.setAvatar(message.getSender().getAvatar());
+        dto.setSender(userSummaryDto);
+
+        return dto;
+    }
+
+    public MessageConversation findOrCreateConversation(Long user1Id, Long user2Id) {
+        User user1 = userRepository.findById(user1Id)
+                .orElseThrow(() -> new IllegalArgumentException("User1 not found"));
+        User user2 = userRepository.findById(user2Id)
+                .orElseThrow(() -> new IllegalArgumentException("User2 not found"));
+        return findOrCreateConversation(user1, user2);
+    }
+
+    private MessageConversation findOrCreateConversation(User user1, User user2) {
+        log.info("Searching for existing conversation between {} and {}", user1.getUsername(), user2.getUsername());
+        return conversationRepository.findConversationByUsers(user1, user2)
+                .orElseGet(() -> {
+                    log.info("No existing conversation found. Creating a new one.");
+                    MessageConversation conversation = new MessageConversation();
+                    conversation = conversationRepository.save(conversation);
+                    log.info("New conversation created with ID: {}", conversation.getId());
+
+                    MessageParticipant participant1 = new MessageParticipant();
+                    participant1.setConversation(conversation);
+                    participant1.setUser(user1);
+                    participantRepository.save(participant1);
+                    log.info("Participant {} added to conversation {}", user1.getUsername(), conversation.getId());
+
+                    MessageParticipant participant2 = new MessageParticipant();
+                    participant2.setConversation(conversation);
+                    participant2.setUser(user2);
+                    participantRepository.save(participant2);
+                    log.info("Participant {} added to conversation {}", user2.getUsername(), conversation.getId());
+
+                    return conversation;
+                });
+    }
+
+    @Transactional(readOnly = true)
+    public List<ConversationDto> getConversations(Long userId) {
+        List<MessageConversation> conversations = conversationRepository.findConversationsByUserIdOrderByLastMessageDesc(userId);
+        return conversations.stream().map(c -> toDto(c, userId)).collect(Collectors.toList());
+    }
+
+    private ConversationDto toDto(MessageConversation conversation, Long userId) {
+        ConversationDto dto = new ConversationDto();
+        dto.setId(conversation.getId());
+        dto.setCreatedAt(conversation.getCreatedAt());
+        if (conversation.getLastMessage() != null) {
+            dto.setLastMessage(toDto(conversation.getLastMessage()));
+        }
+        dto.setParticipants(conversation.getParticipants().stream()
+                .map(p -> {
+                    UserSummaryDto userDto = new UserSummaryDto();
+                    userDto.setId(p.getUser().getId());
+                    userDto.setUsername(p.getUser().getUsername());
+                    userDto.setAvatar(p.getUser().getAvatar());
+                    return userDto;
+                })
+                .collect(Collectors.toList()));
+
+        MessageParticipant self = conversation.getParticipants().stream()
+                .filter(p -> p.getUser().getId().equals(userId))
+                .findFirst()
+                .orElseThrow(() -> new IllegalStateException("Participant not found in conversation"));
+
+        LocalDateTime lastRead = self.getLastReadAt() == null ? LocalDateTime.of(1970, 1, 1, 0, 0) : self.getLastReadAt();
+        // 只计算别人发送给当前用户的未读消息
+        long unreadCount = messageRepository.countByConversationIdAndCreatedAtAfterAndSenderIdNot(conversation.getId(), lastRead, userId);
+        dto.setUnreadCount(unreadCount);
+
+        return dto;
+    }
+
+    @Transactional
+    public ConversationDetailDto getConversationDetails(Long conversationId, Long userId, Pageable pageable) {
+        markConversationAsRead(conversationId, userId);
+
+        MessageConversation conversation = conversationRepository.findById(conversationId)
+                .orElseThrow(() -> new IllegalArgumentException("Conversation not found"));
+
+        Page<Message> messagesPage = messageRepository.findByConversationId(conversationId, pageable);
+        Page<MessageDto> messageDtoPage = messagesPage.map(this::toDto);
+
+        List<UserSummaryDto> participants = conversation.getParticipants().stream()
+                .map(p -> {
+                    UserSummaryDto userDto = new UserSummaryDto();
+                    userDto.setId(p.getUser().getId());
+                    userDto.setUsername(p.getUser().getUsername());
+                    userDto.setAvatar(p.getUser().getAvatar());
+                    return userDto;
+                })
+                .collect(Collectors.toList());
+
+        ConversationDetailDto detailDto = new ConversationDetailDto();
+        detailDto.setId(conversation.getId());
+        detailDto.setParticipants(participants);
+        detailDto.setMessages(messageDtoPage);
+
+        return detailDto;
+    }
+
+    @Transactional
+    public void markConversationAsRead(Long conversationId, Long userId) {
+        MessageParticipant participant = participantRepository.findByConversationIdAndUserId(conversationId, userId)
+                .orElseThrow(() -> new IllegalArgumentException("Participant not found"));
+        participant.setLastReadAt(LocalDateTime.now());
+        participantRepository.save(participant);
+    }
+
+    @Transactional(readOnly = true)
+    public long getUnreadMessageCount(Long userId) {
+        List<MessageParticipant> participations = participantRepository.findByUserId(userId);
+        long totalUnreadCount = 0;
+        for (MessageParticipant p : participations) {
+            LocalDateTime lastRead = p.getLastReadAt() == null ? LocalDateTime.of(1970, 1, 1, 0, 0) : p.getLastReadAt();
+            // 只计算别人发送给当前用户的未读消息
+            totalUnreadCount += messageRepository.countByConversationIdAndCreatedAtAfterAndSenderIdNot(p.getConversation().getId(), lastRead, userId);
+        }
+        return totalUnreadCount;
+    }
+}