10 KiB
10 KiB
私信列表
本节实现的功能：
- 私信列表：
- 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
- 支持分页显示
- 私信详情
- 查询某个会话所包含的私信
- 支持分页显示
- 访问私信详情时，将显示的私信设为已读状态
message 表中有个字段 conservation_id ，这个字段的设计方式是：比如用户 id 112 给 113 发消息，或者 113 给 112 发消息，这两个会话的 conservation_id 都是 112_113。当然，这个字段是冗余的，我们可以通过 from_id 和 to_id 推演出来，但是有了这个字段方便于后面的查询等操作
注意：from_id = 1 代表这是一个系统通知，后续会开发此功能
DAO
@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
* @param userId 用户 id
* @param offset 每页的起始索引
* @param limit 每页显示多少条数据
* @return
*/
List<Message> selectConversations(int userId, int offset, int limit);
/**
* 查询当前用户的会话数量
* @param userId
* @return
*/
int selectConversationCount(int userId);
/**
* 查询某个会话所包含的私信列表
* @param conversationId
* @param offset
* @param limit
* @return
*/
List<Message> selectLetters(String conversationId, int offset, int limit);
/**
* 查询某个会话所包含的私信数量
* @param conversationId
* @return
*/
int selectLetterCount(String conversationId);
/**
* 查询未读私信的数量
* @param userId
* @param conversationId conversationId = null, 则查询该用户所有会话的未读私信数量
* conversationId != null, 则查询该用户某个会话的未读私信数量
* @return
*/
int selectLetterUnreadCount(int userId, String conversationId);
/**
* 修改消息的状态
* @param ids
* @param status
* @return
*/
int updateStatus(List<Integer> ids, int status);
}
对应的 mapper.xml
<mapper namespace="com.greate.community.dao.MessageMapper">
<sql id="selectFields">
id, from_id, to_id, conversation_id, content, status, create_time
</sql>
<!--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）-->
<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>
<!--查询当前用户的会话数量-->
<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 = #{toId})
group by conversation_id
) as m
</select>
<!--查询某个会话所包含的私信列表-->
<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>
<!--查询某个会话所包含的私信数量-->
<select id="selectLetterCount" resultType="int">
select count(id)
from message
where status != 2
and from_id != 1
and conversation_id = #{conversationId}
</select>
<!--查询未读私信的数量-->
<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>
<!--修改消息的状态-->
<update id="updateStatus">
update message
set status = #{status}
where id in
<foreach collection="ids" item="id" open="(" separator="," close=")">
#{id}
</foreach>
</update>
</mapper>
Service
@Service
public class MessageService {
@Autowired
private MessageMapper 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
public List<Message> findConversations(int userId, int offset, int limit) {
return messageMapper.selectConversations(userId, offset, limit);
}
// 查询当前用户的会话数量
public int findConversationCout(int userId) {
return messageMapper.selectConversationCount(userId);
}
// 查询某个会话所包含的私信列表
public List<Message> findLetters(String conversationId, int offset, int limit) {
return messageMapper.selectLetters(conversationId, offset, limit);
}
// 查询某个会话所包含的私信数量
public int findLetterCount(String conversationId) {
return messageMapper.selectLetterCount(conversationId);
}
// 查询未读私信的数量
public int findLetterUnreadCount(int userId, String conversationId) {
return messageMapper.selectLetterUnreadCount(userId, conversationId);
}
// 读取私信(将私信状态设置为已读)
public int readMessage(List<Integer> ids) {
return messageMapper.updateStatus(ids, 1);
}
}
Controller
@Controller
public class MessageController {
@Autowired
private HostHolder hostHolder;
@Autowired
private MessageService messageService;
@Autowired
private UserService userService;
/**
* 私信列表
* @param model
* @param page
* @return
*/
@GetMapping("/letter/list")
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.findConversationCout(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); // 私信
map.put("letterCount", messageService.findLetterCount(
message.getConversationId())); // 私信数量
map.put("unreadCount", messageService.findLetterUnreadCount(
user.getId(), message.getConversationId())); // 未读私信数量
int targetId = user.getId() == message.getFromId() ? message.getToId() : message.getFromId();
map.put("target", userService.findUserById(targetId)); // 私信对方
conversations.add(map);
}
}
model.addAttribute("conversations", conversations);
// 查询当前用户的所有未读私信数量
int letterUnreadCount = messageService.findLetterUnreadCount(user.getId(), null);
model.addAttribute("letterUnreadCount", letterUnreadCount);
return "/site/letter";
}
/**
* 私信详情页
* @param conversationId
* @param page
* @param model
* @return
*/
@GetMapping("/letter/detail/{conversationId}")
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));
// 将私信列表中的未读消息改为已读
List<Integer> ids = getUnreadLetterIds(letterList);
if (!ids.isEmpty()) {
messageService.readMessage(ids);
}
return "/site/letter-detail";
}
/**
* 获取私信对方对象
* @param conversationId
* @return
*/
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);
}
}
/**
* 获取当前登录用户未读私信的 id
* @param letterList
* @return
*/
private List<Integer> getUnreadLetterIds(List<Message> letterList) {
List<Integer> ids = new ArrayList<>();
if (letterList != null) {
for (Message message : letterList) {
// 当前用户是私信的接收者且该私信处于未读状态
if (hostHolder.getUser().getId() == message.getToId() && message.getStatus() == 0) {
ids.add(message.getId());
}
}
}
return ids;
}
}
前端
letter-detail
li th:each="map:${letters}">
<img th:src="${map.fromUser.headerUrl}" alt="用户头像" >
<strong th:utext="${map.fromUser.username}"></strong>
<div th:utext="${map.letter.content}"></div>
</li>