牛客网社区项目——p3.7私信列表

首先建立Message实体类，代码略

DAO层代码

@Mapper
public interface MessageMapper {

    //查询当前用户的会话列表，针对每个会话只返回一条最新的私信
    List<Message> selectConversations(int userId, int offset, int limit);
    //查询当前用户会话数量
    int selectConversationCount(int userId);
    //查询某个会话包含的私信列表
    List<Message> selectLetters(String conversationId, int offset, int limit);
    //查询某个会话包含的私信数量
    int selectLetterCount(String conversationId);
    //查询未读私信的数量
    int selectLetterUnreadCount(int userId, String conversationId);
}

配置对应的mapper.xml文件

对DAO层，以及mapper中的代码进行测试，在MapperTests类中添加以下代码进行测试

@Test
    public void testSelectLetters(){
        List<Message> list= messageMapper.selectConversations(111, 0, 20);
        for(Message message : list){
            System.out.println(message);
        }
        int count =messageMapper.selectConversationCount(111);
        System.out.println(count);
        list = messageMapper.selectLetters("111_112", 0, 20);
        for(Message message : list){
            System.out.println(message.getContent());
        }
        count = messageMapper.selectLetterCount("111_112");
        System.out.println(count);
        count = messageMapper.selectLetterUnreadCount(131, "111_131");
        System.out.println(count);
    }

在服务层编写如下代码

@Service
public class MessageService {
    @Autowired(required = false)
    private MessageMapper messageMapper;
    @Autowired
    private SensitiveFilter sensitiveFilter;
    public List<Message> findConversations(int userId, int offset, int limit){
        return messageMapper.selectConversations(userId, offset, limit);
    }
    public int findConversationCount(int userId){
        return messageMapper.selectConversationCount(userId);
    }
    public List<Message> findLetters(String conversationId, int offset, int limit){
        return messageMapper.selectLetters(conversationId, offset, limit);
    }
    public int findLetterCount(String conversationId){
        return messageMapper.selectLetterCount(conversationId);
    }
    public int findLetterUnreadCount(int userId, String conversationId){
        return messageMapper.selectLetterUnreadCount(userId, conversationId);
    }
}

表现层的代码如下

@Controller
public class MessageController {

    @Autowired
    private MessageService messageService;

    @Autowired
    private HostHolder hostHolder;

    @Autowired
    private UserService userService;

    //私信列表
    @RequestMapping(path = "/letter/list", method = RequestMethod.GET)
    public String getLetterList(Model model, Page page){
        User user = hostHolder.getUser();
        //分页信息
        page.setLimit(5);
        page.setPath("/letter/list");
        page.setRows(messageService.findConversationCount(user.getId()));
        //会话列表
        List<Message> conversationList = messageService.findConversations(
                user.getId(), page.getOffset(), page.getLimit());
        List<Map<String, Object>> conversations = new ArrayList<>();
        if(conversationList != null){
            for(Message message : conversationList){
                Map<String, Object> map = new HashMap<>();
                map.put("conversation", message);
                map.put("letterCount", messageService.findLetterCount(message.getConversationId()));
                map.put("unreadCount", messageService.findLetterUnreadCount(user.getId(), message.getConversationId()));
                int targetId = user.getId() == message.getFromId() ? message.getToId() : message.getFromId();
                map.put("target", userService.findUserById(targetId));
                conversations.add(map);
            }
        }
        model.addAttribute("conversations", conversations);

        //查询未读消息数量
        int letterUnreadCount = messageService.findLetterUnreadCount(user.getId(), null);
        model.addAttribute("letterUnreadCount", letterUnreadCount);

        return "/site/letter";
    }

    @RequestMapping(path = "/letter/detail/{conversationId}", method = RequestMethod.GET)
    public String getLetterDetail(@PathVariable("conversationId") String conversationId, Page page, Model model){
        //分页信息
        page.setLimit(5);
        page.setPath("/letter/detail/" + conversationId);
        page.setRows(messageService.findLetterCount(conversationId));

        //私信列表
        List<Message> letterList = messageService.findLetters(conversationId, page.getOffset(), page.getLimit());
        List<Map<String, Object>> letters = new ArrayList<>();

        if(letterList != null){
            for(Message message : letterList){
                Map<String, Object> map = new HashMap<>();
                map.put("letter", message);
                map.put("fromUser", userService.findUserById(message.getFromId()));
                letters.add(map);
            }
        }
        model.addAttribute("letters", letters);
        //私信目标
        model.addAttribute("target", getLetterTarget(conversationId));
        return "/site/letter-detail";
    }

    private User getLetterTarget(String conversationId){
        String[] ids = conversationId.split("_");
        int id0 = Integer.parseInt(ids[0]);
        int id1 = Integer.parseInt(ids[1]);

        if(hostHolder.getUser().getId() == id0){
            return userService.findUserById(id1);
        }else{
            return userService.findUserById(id0);
        }
    }
}

再配置对应的.html文件即可