社区网站项目3.7 私信列表

  私信列表：

（1）查询当前用户的会话列表，每个会话只显示一条最新的私信。

（2）支持分页显示。

  私信详情：

（1）查询某个会话所包含的私信。

（2）支持分页显示。

  在entity包下新建Message类，在dao包下新建MessageMapper接口类，添加

//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);

    //查询当前用户的会话数量。
    int selectConversationCount(int userId);

    //查询某个会话所包含的私信列表
    List<Message> selectLetters(String conversationId, int offset, int limit);

    //查询某个会话所包含的私信数量。
    int selectLetterCount(String conversationId);
    
    //查询未读私信的数量
    int selectLetterUnreadCount(int userId,String conversationId);
           

  在message-mapper.xml里，添加

<select id="selectConversations" resultType="Message">
        select <include refid="selectFields"></include>
        from message
        where id in (
            select max(id) from message
            where status != 2
            and from_id != 1
            and (from_id = #{userId} or to_id = #{userId})
            group by conversation_id
        )
        order by id desc
        limit #{offset}, #{limit}
    </select>

    <select id="selectConversationCount" resultType="int">
        select count(m.maxid) from(
            select max(id) as maxid from message
            where status != 2
            and from_id != 1
            and (from_id = #{userId} or to_id = #{userId})
            group by conversation_id
        ) as m
    </select>
    <select id="selectLetters" resultType="Message">
        select<include refid="selectFields"></include>
        from message
        where status != 2
        and from_id != 1
        and conversation_id = #{conversationId}
        order by id desc
        limit #{offset},#{limit}
    </select>

    <select id="selectLetterCount" resultType="int">
        select count(id)
        from message
        where status != 2
        and from_id != 1
        and conversation_id = #{conversationId}
    </select>
    <select id="selectLetterUnreadCount" resultType="int">
        select count(id)
        from message
        where status = 0
        and from_id != 1
        and to_id = #{userId}
        <if test="conversationId!=null">
            and conversation_id = #{conversationId}
        </if>
    </select>
           

  此时可以在MapperTests测试类里对MessageMapper里的方法进行测试

@Test
    public void testSelectLetters(){
        List<Message> list = messageMapper.selectConversations(111,0,20); //offset为0表示查第一页，limit为20表示一页内显示的最大数目
        for(Message message:list){
            System.out.println(message);
        }

        int count = messageMapper.selectConversationCount(111);
        System.out.println(count);

        list = messageMapper.selectLetters("111_112",0,10);
        for(Message message:list){
            System.out.println(message);
        }

        count = messageMapper.selectLetterCount("111_112");
        System.out.println(count);

        count = messageMapper.selectLetterUnreadCount(131,"111_131");
        System.out.println(count);
    }
           

  没有问题之后，在MesssageService类里，添加

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);
    }
           

  在MessageController类里，添加

// 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);
        int noticeUnreadCount = messageService.findNoticeUnreadCount(user.getId(),null);
        model.addAttribute("noticeUnreadCount",noticeUnreadCount);  //后来添加的

        return "/site/letter";
    }
           

  在index.html里，把消息的链接改成对应的，在letter.html里，把会话列表相关内容该为对应的。

  再完成私信列表的功能。在MessageController类里添加

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));

        //设置已读
        List<Integer> ids =  getLetterIds(letterList); //获取未读消息
        if(!ids.isEmpty()){
            messageService.readMessage(ids);
        }

        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);
        }
    }
           

  在letter.html里，把私信列表的链接改成对应的，在letter-detail.html里，把私信列表相关内容该为对应的，并为返回按钮添加一个back方法的js脚本。