问答平台（3），发送私信

发送私信

- 采用异步的方式发送私信。
- 发送成功后刷新私信列表。

---

数据访问层

// MessageMapper.java
// 新增消息
int insertMessage(Message message);

// 修改消息的状态
int updateStatus(List<Integer> ids, int status);

• message-mapper.xml 里写sql

  <sql id="insertFields">
      from_id, to_id, conversation_id, content, status, create_time
  </sql>
  
  <insert id="insertMessage" parameterType="Message" keyProperty="id">
      insert into message(<include refid="insertFields"></include>)
      values(#{fromId},#{toId},#{conversationId},#{content},#{status},#{createTime})
  </insert>
  
  <update id="updateStatus">
      update message set status = #{status}
      where id in
      <foreach collection="ids" item="id" open="(" separator="," close=")">
          #{id}
      </foreach>
  </update>

---

业务层

// MessageService.java
@Autowired
private SensitiveFilter sensitiveFilter;

public int addMessage(Message message) {
    message.setContent(HtmlUtils.htmlEscape(message.getContent()));
    message.setContent(sensitiveFilter.filter(message.getContent()));
    return messageMapper.insertMessage(message);
}

public int readMessage(List<Integer> ids) {
    return messageMapper.updateStatus(ids, 1);
}

// UserService.java
public User findUserByName(String username) {
    return userMapper.selectByName(username);
}

---

表现层

// MessageController.java
@RequestMapping(path = "/letter/send", method = RequestMethod.POST)
@ResponseBody
public String sendLetter(String toName, String content) {
    User target = userService.findUserByName(toName);
    if (target == null) {
        return CommunityUtil.getJSONString(1, "目标用户不存在!");
    }

    Message message = new Message();
    message.setFromId(hostHolder.getUser().getId());
    message.setToId(target.getId());
    if (message.getFromId() < message.getToId()) {
        message.setConversationId(message.getFromId() + "_" + message.getToId());
    } else {
        message.setConversationId(message.getToId() + "_" + message.getFromId());
    }
    message.setContent(content);
    message.setStatus(0);
    message.setCreateTime(new Date());
    messageService.addMessage(message);

    return CommunityUtil.getJSONString(0);
}

• 访问私信详情时，将显示的私信设置为已读状态。

  // MessageController.java
  private List<Integer> getLetterIds(List<Message> letterList) {
      List<Integer> ids = new ArrayList<>();
  
      if (letterList != null) {
          for (Message message : letterList) {
              if (hostHolder.getUser().getId() == message.getToId() && message.getStatus() == 0) {
                  ids.add(message.getId());
              }
          }
      }
  
      return ids;
  }
  
  @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));
  
      // 设置已读
      List<Integer> ids = getLetterIds(letterList);
      if (!ids.isEmpty()) {
          messageService.readMessage(ids);
      }
  
      return "/site/letter-detail";
  }

---

页面

• letter.html：处理弹出框（发私信）

  <!-- 内容 -->
  <!-- 弹出框 -->
  <div class="modal-body">
      <form>
          <div class="form-group">
              <label for="recipient-name" class="col-form-label">发给：</label>
              <input type="text" class="form-control" id="recipient-name">
          </div>
          <div class="form-group">
              <label for="message-text" class="col-form-label">内容：</label>
              <textarea class="form-control" id="message-text" rows="10"></textarea>
          </div>
      </form>
  </div>
  <!-- 提示框 -->
  <div class="modal-content">
      <div class="modal-header">
          <h5 class="modal-title" id="hintModalLabel">提示</h5>
      </div>
      <div class="modal-body" id="hintBody">
          发送完毕!
      </div>
  </div>

• letter.js

  // send_letter()
  function send_letter() {
      $("#sendModal").modal("hide");
  
      var toName = $("#recipient-name").val();
      var content = $("#message-text").val();
      $.post(
          CONTEXT_PATH + "/letter/send",
          {"toName": toName, "content": content},
          function (data) {
              data = $.parseJSON(data);
              if (data.code == 0) {
                  $("#hintBody").text("发送成功!");
              } else {
                  $("#hintBody").text(data.msg);
              }
  
              $("#hintModal").modal("show");
              setTimeout(function () {
                  $("#hintModal").modal("hide");
                  window.location.reload();
              }, 2000);
          }
      );
  }

• letter-detail.html：处理弹出框（发送私信给谁）

  <!-- 内容 -->
  <!-- 弹出框 -->
  <div class="modal-body">
      <form>
          <div class="form-group">
              <label for="recipient-name" class="col-form-label">发给：</label>
              <input type="text" class="form-control" id="recipient-name"
                      th:value="${target.username}">
          </div>
          <div class="form-group">
              <label for="message-text" class="col-form-label">内容：</label>
              <textarea class="form-control" id="message-text" rows="10"></textarea>
          </div>
      </form>
  </div>