1、项目展示图

登录

登录成功

互动

2、websocket介绍

websocket是一种全双工的连接，即服务器和客户端之间建立了一次连接后，两者之间就会一直打开这个通道，就可以相互进行通信。相对于传统单双工的http请求，节省很多资源，不需要一直轮询服务器。

3、springboot代码(主要是写websocket相关的方法，比如创建连接事件，接收消息以及发送消息事件，关闭连接事件)

package com.example.message.WebSocket;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import com.gcp.basicproject.util.ParamUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Component;

import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.ConcurrentHashMap;

/**
 * @author Admin
 */
@ServerEndpoint("/chat/{name}")
@Component
public class AllWebSocketService {

    static Logger log = LoggerFactory.getLogger(AllWebSocketService.class);

    private static int onlineCount = 0;

    private static ConcurrentHashMap<String,AllWebSocketService> webSocketServerMap = new ConcurrentHashMap<>();

    private Session session;

    private String name = "";

    private static ApplicationContext applicationContext;

    /**
     * 解决引入外部类方法
     * @param context
     */
    public static void setApplicationContext(ApplicationContext context){
        applicationContext = context;
    }

    /**
     * 建立连接
     * @param session
     * @param name
     */
    @OnOpen
    public void onOpen(Session session,@PathParam("name") String name){
        this.session = session;
        webSocketServerMap.put(name,this);
        this.name = name;
        addOnlineCount();
        log.info("用户连接："+name+"，当前在线人数为："+getOnlineCount());
        try{
            sendMessage("进入聊天室成功");
        }catch (IOException e){
            log.error("用户："+name+",连接失败！！");
        }
    }

    /**
     * 关闭连接
     */
    @OnClose
    public void onClose(){
        subOnlineCount();
        webSocketServerMap.remove(name);
        log.info("用户退出："+name+",当前在线人数为："+getOnlineCount());
    }


    @OnMessage
    public void onMessage(String message){
        log.info("用户消息："+name+",报文："+message);
        if(ParamUtil.notEmpty(message)){
            log.info(message);
            JSONObject jsonObject = JSON.parseObject(message);
            jsonObject.put("name",this.name);
            webSocketServerMap.forEach((u,m)->{
                if(name.contains(u)){
                    return;
                }
                try {
                    m.sendMessage(jsonObject.toJSONString());
                } catch (IOException e) {
                    e.printStackTrace();
                }
            });
        }
    }

    /**
     * 服务器推送消息
     * @param message
     * @throws IOException
     */
    public void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
    }


    /**
     * 获取在线人数
     * @return
     */
    public static  synchronized  int getOnlineCount(){
        return onlineCount;
    }

    /**
     * 上线
     */
    public static  synchronized  void addOnlineCount(){
        AllWebSocketService.onlineCount++;
    }

    /**
     * 离线
     */
    public static  synchronized void subOnlineCount(){
        AllWebSocketService.onlineCount--;
    }

}

4、vue代码(主要是写连接本地的websocket，接收、发送和显示消息)

<!-- 聊天室 -->
<template>
  <h1>聊天室</h1>
  <el-scrollbar height="400px" style="border:1px solid #1813131f">
    <el-tag v-for="item in list" :key="item" class="scrollbar-demo-item" :style="`justify-content: ${item.type}`">{{
        item.name
    }}:{{ item.content }}</el-tag>
  </el-scrollbar>
  发送消息：<el-input v-model="msg"></el-input>
  <el-button @click="sendMesage(msg)">发送消息</el-button>
  <el-button text @click="dialogFormVisible = true">登录</el-button>

  <el-dialog v-model="dialogFormVisible" title="登录">
    请输入用户昵称:
    <el-input v-model="name" autocomplete="off" />
    <template #footer>
      <span class="dialog-footer">
        <el-button type="primary" @click="login()">确认</el-button>
      </span>
    </template>
  </el-dialog>
  <router-link to="/">返回首页</router-link>
</template>

<script>
import { onBeforeUnmount, reactive, ref } from 'vue'
import { ElMessage } from 'element-plus'

export default {
  name: "chat",
  setup() {
    const list = reactive([]);
    let socket = null;

    // Websoket连接成功事件
    const websocketonopen = (res) => {
      ElMessage.success("WebSocket连接成功");
    };
    // Websoket接收消息事件
    const websocketonmessage = (res) => {
      if (res.data) {
        ElMessage.success("接收到消息：" + JSON.parse(res.data).content);
        message.content = JSON.parse(res.data).content;
        message.name = JSON.parse(res.data).name;
        message.type = 'left';
        list.push(JSON.parse(JSON.stringify(message)));
        console.log(list);
      }
    };
    // Websoket连接错误事件
    const websocketonerror = (res) => {
      ElMessage.error("连接错误");
    };
    // Websoket断开事件
    const websocketclose = (res) => {
      ElMessage.error("断开连接");
    };

    let message = reactive(
      {
        name: "",
        content: "",
        type: ''
      }
    );
    let msg = ref("");
    let name = ref("");
    const dialogFormVisible = ref(false);

    const sendMesage = (m) => {
      if (name.value == "") {
        ElMessage.warning("未登录，无法发送消息");
      } else {
        ElMessage.success("发送消息：" + m)
        message.content = m;
        message.name = name.value;
        message.type = 'right';
        socket.send(JSON.stringify(message));
        //解决message对象只有一个，push修改所有message对象的问题
        list.push(JSON.parse(JSON.stringify(message)));
        console.log(list);
      }
    }
    // 创建 websocket 的实例
    const createSocket = () => {
      const wsurl = "ws://localhost:8075/chat/" + name.value;
      socket = new WebSocket(wsurl);
      socket.onopen = websocketonopen;
      socket.onmessage = websocketonmessage;
      socket.onerror = websocketonerror;
      socket.onclose = websocketclose;
    };
    //登录聊天室
    const login = () => {
      console.log(name);
      createSocket();
      dialogFormVisible.value = false;
    }

    // 组件被销毁之前，清空 sock 对象
    onBeforeUnmount(() => {
      // 关闭连接
      websocketclose;

      // 销毁 websocket 实例对象
      socket = null;
    });
    //建立连接，创建websocket实例

    return {
      name,
      list,
      msg,
      message,
      dialogFormVisible,
      sendMesage,
      createSocket,
      login
    };
  },
};

</script>

<style scoped>
.read-the-docs {
  color: #888;
}

.scrollbar-demo-item {
  display: flex;
  align-items: center;
  height: 30px;
  margin: 10px;
  text-align: left;
  border-radius: 4px;
}
</style>