一、前言

本文将基于 SpringBoot + Vue + WebSocket 实现一个简单的在线聊天功能

页面如下:

在线体验地址：http://www.zhengqingya.com:8101

二、SpringBoot + Vue + WebSocket 实现在线聊天

1、引入websocket依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-websocket</artifactId>
</dependency>

2、websocket 配置类

@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

3、websocket 处理类Controller

@Slf4j
@Component
@ServerEndpoint("/groupChat/{sid}/{userId}")
public class WebSocketServerController {

    /**
     * 房间号 -> 组成员信息
     */
    private static ConcurrentHashMap<String, List<Session>> groupMemberInfoMap = new ConcurrentHashMap<>();
    /**
     * 房间号 -> 在线人数
     */
    private static ConcurrentHashMap<String, Set<Integer>> onlineUserMap = new ConcurrentHashMap<>();

    /**
     * 收到消息调用的方法，群成员发送消息
     *
     * @param sid:房间号
     * @param userId：用户id
     * @param message：发送消息
     */
    @OnMessage
    public void onMessage(@PathParam("sid") String sid, @PathParam("userId") Integer userId, String message) {
        List<Session> sessionList = groupMemberInfoMap.get(sid);
        Set<Integer> onlineUserList = onlineUserMap.get(sid);
        // 先一个群组内的成员发送消息
        sessionList.forEach(item -> {
            try {
                // json字符串转对象
                MsgVO msg = JSONObject.parseObject(message, MsgVO.class);
                msg.setCount(onlineUserList.size());
                // json对象转字符串
                String text = JSONObject.toJSONString(msg);
                item.getBasicRemote().sendText(text);
            } catch (IOException e) {
                e.printStackTrace();
            }
        });
    }

    /**
     * 建立连接调用的方法，群成员加入
     *
     * @param session
     * @param sid
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("sid") String sid, @PathParam("userId") Integer userId) {
        List<Session> sessionList = groupMemberInfoMap.computeIfAbsent(sid, k -> new ArrayList<>());
        Set<Integer> onlineUserList = onlineUserMap.computeIfAbsent(sid, k -> new HashSet<>());
        onlineUserList.add(userId);
        sessionList.add(session);
        // 发送上线通知
        sendInfo(sid, userId, onlineUserList.size(), "上线了~");
    }


    public void sendInfo(String sid, Integer userId, Integer onlineSum, String info) {
        // 获取该连接用户信息
        User currentUser = ApplicationContextUtil.getApplicationContext().getBean(UserMapper.class).selectById(userId);
        // 发送通知
        MsgVO msg = new MsgVO();
        msg.setCount(onlineSum);
        msg.setUserId(userId);
        msg.setAvatar(currentUser.getAvatar());
        msg.setMsg(currentUser.getNickName() + info);
        // json对象转字符串
        String text = JSONObject.toJSONString(msg);
        onMessage(sid, userId, text);
    }

    /**
     * 关闭连接调用的方法，群成员退出
     *
     * @param session
     * @param sid
     */
    @OnClose
    public void onClose(Session session, @PathParam("sid") String sid, @PathParam("userId") Integer userId) {
        List<Session> sessionList = groupMemberInfoMap.get(sid);
        sessionList.remove(session);
        Set<Integer> onlineUserList = onlineUserMap.get(sid);
        onlineUserList.remove(userId);
        // 发送离线通知
        sendInfo(sid, userId, onlineUserList.size(), "下线了~");
    }

    /**
     * 传输消息错误调用的方法
     *
     * @param error
     */
    @OnError
    public void OnError(Throwable error) {
        log.info("Connection error");
    }
}

4、websocket 消息显示类

@Data
@ApiModel(description = "websocket消息内容")
public class MsgVO {

    @ApiModelProperty(value = "用户id")
    private Integer userId;

    @ApiModelProperty(value = "用户名")
    private String username;

    @ApiModelProperty(value = "用户头像")
    private String avatar;

    @ApiModelProperty(value = "消息")
    private String msg;

    @ApiModelProperty(value = "在线人数")
    private int count;

}

5、前端页面

温馨小提示：当用户登录成功之后，可以发起websocket连接，存在store中…

下面只是单页面的简单实现

<template>
  <div class="chat-box">
    <header>聊天室 (在线:{{count}}人)</header>
    <div class="msg-box" ref="msg-box">
      <div
        v-for="(i,index) in list"
        :key="index"
        class="msg"
        :style="i.userId == userId?'flex-direction:row-reverse':''"
      >
        <div class="user-head">
          <img :src="i.avatar" height="30" width="30" :title="i.username">
        </div>
        <div class="user-msg">
          <span :style="i.userId == userId?' float: right;':''" :class="i.userId == userId?'right':'left'">{{i.content}}</span>
        </div>
      </div>
    </div>
    <div class="input-box">
      <input type="text" ref="sendMsg" v-model="contentText" @keyup.enter="sendText()" />
      <div class="btn" :class="{['btn-active']:contentText}" @click="sendText()">发送</div>
    </div>
  </div>
</template>

<script>
  export default {
    data() {
      return {
        ws: null,
        count: 0,
        userId: this.$store.getters.id, // 当前用户ID
        username: this.$store.getters.name, // 当前用户昵称
        avatar: this.$store.getters.avatar, // 当前用户头像
        list: [], // 聊天记录的数组
        contentText: "" // input输入的值
      };
    },
    mounted() {
      this.initWebSocket();
    },
    destroyed() {
      // 离开页面时关闭websocket连接
      this.ws.onclose(undefined);
    },
    methods: {
      // 发送聊天信息
      sendText() {
        let _this = this;
        _this.$refs["sendMsg"].focus();
        if (!_this.contentText) {
          return;
        }
        let params = {
          userId: _this.userId,
          username: _this.username,
          avatar: _this.avatar,
          msg: _this.contentText,
          count: _this.count
        };
        _this.ws.send(JSON.stringify(params)); //调用WebSocket send()发送信息的方法
        _this.contentText = "";
        setTimeout(() => {
          _this.scrollBottm();
        }, 500);
      },
      // 进入页面创建websocket连接
      initWebSocket() {
        let _this = this;
        // 判断页面有没有存在websocket连接
        if (window.WebSocket) {
          var serverHot =  window.location.hostname;
          let sip = '房间号'
          // 填写本地IP地址 此处的 :9101端口号 要与后端配置的一致！
          var url = 'ws://' + serverHot + ':9101' + '/groupChat/' + sip + '/' + this.userId; // `ws://127.0.0.1/9101/groupChat/10086/聊天室`
          let ws = new WebSocket(url);
          _this.ws = ws;
          ws.onopen = function(e) {
            console.log("服务器连接成功: " + url);
          };
          ws.onclose = function(e) {
            console.log("服务器连接关闭: " + url);
          };
          ws.onerror = function() {
            console.log("服务器连接出错: " + url);
          };
          ws.onmessage = function(e) {
            //接收服务器返回的数据
            let resData = JSON.parse(e.data)
            _this.count = resData.count;
            _this.list = [
              ..._this.list,
              { userId: resData.userId, username: resData.username, avatar: resData.avatar, content: resData.msg }
            ];
          };
        }
      },
      // 滚动条到底部
      scrollBottm() {
          let el = this.$refs["msg-box"];
          el.scrollTop = el.scrollHeight;
      }
    }
  };
</script>

<style lang="scss" scoped>
  .chat-box {
    margin: 0 auto;
    background: #fafafa;
    position: absolute;
    height: 100%;
    width: 100%;
    max-width: 700px;
  header {
    position: fixed;
    width: 100%;
    height: 3rem;
    background: #409eff;
    max-width: 700px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    color: white;
    font-size: 1rem;
  }
  .msg-box {
    position: absolute;
    height: calc(100% - 6.5rem);
    width: 100%;
    margin-top: 3rem;
    overflow-y: scroll;
  .msg {
    width: 95%;
    min-height: 2.5rem;
    margin: 1rem 0.5rem;
    position: relative;
    display: flex;
    justify-content: flex-start !important;
  .user-head {
    min-width: 2.5rem;
    width: 20%;
    width: 2.5rem;
    height: 2.5rem;
    border-radius: 50%;
    background: #f1f1f1;
    display: flex;
    justify-content: center;
    align-items: center;
  .head {
    width: 1.2rem;
    height: 1.2rem;
  }
  // position: absolute;
  }
  .user-msg {
    width: 80%;
  // position: absolute;
    word-break: break-all;
    position: relative;
    z-index: 5;
  span {
    display: inline-block;
    padding: 0.5rem 0.7rem;
    border-radius: 0.5rem;
    margin-top: 0.2rem;
    font-size: 0.88rem;
  }
  .left {
    background: white;
    animation: toLeft 0.5s ease both 1;
  }
  .right {
    background: #53a8ff;
    color: white;
    animation: toright 0.5s ease both 1;
  }
  @keyframes toLeft {
    0% {
      opacity: 0;
      transform: translateX(-10px);
    }
    100% {
      opacity: 1;
      transform: translateX(0px);
    }
  }
  @keyframes toright {
    0% {
      opacity: 0;
      transform: translateX(10px);
    }
    100% {
      opacity: 1;
      transform: translateX(0px);
    }
  }
  }
  }
  }
  .input-box {
    padding: 0 0.5rem;
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 3.5rem;
    background: #fafafa;
    box-shadow: 0 0 5px #ccc;
    display: flex;
    justify-content: space-between;
    align-items: center;
  input {
    height: 2.3rem;
    display: inline-block;
    width: 100%;
    padding: 0.5rem;
    border: none;
    border-radius: 0.2rem;
    font-size: 0.88rem;
  }
  .btn {
    height: 2.3rem;
    min-width: 4rem;
    background: #e0e0e0;
    padding: 0.5rem;
    font-size: 0.88rem;
    color: white;
    text-align: center;
    border-radius: 0.2rem;
    margin-left: 0.5rem;
    transition: 0.5s;
  }
  .btn-active {
    background: #409eff;
  }
  }
  }
</style>

本文案例demo源码

https://gitee.com/zhengqingya/xiao-xiao-su