第一步：在ruoyi-framework模块的pom.xml里添加websocket的jar包

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

第二步：在framework包下新建websocket包，添加一下4个文件

1、WebSocketConfig

package com.ruoyi.framework.websocket;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;

/**
 * 开启WebSocket支持
 */
@Configuration
public class WebSocketConfig {
    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

2、WebSocketServer

package com.ruoyi.framework.websocket;

import java.util.concurrent.Semaphore;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

/**
 * websocket 消息处理
 *
 * @author ruoyi
 */
@Component
@ServerEndpoint("/websocket/message")
public class WebSocketServer
{
    /**
     * WebSocketServer 日志控制器
     */
    private static final Logger LOGGER = LoggerFactory.getLogger(WebSocketServer.class);

    /**
     * 默认最多允许同时在线人数100
     */
    public static int socketMaxOnlineCount = 100;

    private static Semaphore socketSemaphore = new Semaphore(socketMaxOnlineCount);

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session) throws Exception
    {
        boolean semaphoreFlag = false;
        // 尝试获取信号量
        semaphoreFlag = SemaphoreUtils.tryAcquire(socketSemaphore);
        if (!semaphoreFlag)
        {
            // 未获取到信号量
            LOGGER.error("\n 当前在线人数超过限制数- {}", socketMaxOnlineCount);
            WebSocketUsers.sendMessageToUserByText(session, "当前在线人数超过限制数：" + socketMaxOnlineCount);
            session.close();
        }
        else
        {
            // 添加用户
            WebSocketUsers.put(session.getId(), session);
            LOGGER.info("\n 建立连接 - {}", session);
            LOGGER.info("\n 当前人数 - {}", WebSocketUsers.getUsers().size());
            WebSocketUsers.sendMessageToUserByText(session, "连接成功");
        }
    }

    /**
     * 连接关闭时处理
     */
    @OnClose
    public void onClose(Session session)
    {
        LOGGER.info("\n 关闭连接 - {}", session);
        // 移除用户
        WebSocketUsers.remove(session.getId());
        // 获取到信号量则需释放
        SemaphoreUtils.release(socketSemaphore);
    }

    /**
     * 抛出异常时处理
     */
    @OnError
    public void onError(Session session, Throwable exception) throws Exception
    {
        if (session.isOpen())
        {
            // 关闭连接
            session.close();
        }
        String sessionId = session.getId();
        LOGGER.info("\n 连接异常 - {}", sessionId);
        LOGGER.info("\n 异常信息 - {}", exception);
        // 移出用户
        WebSocketUsers.remove(sessionId);
        // 获取到信号量则需释放
        SemaphoreUtils.release(socketSemaphore);
    }

    /**
     * 服务器接收到客户端消息时调用的方法
     */
    @OnMessage
    public void onMessage(String message, Session session)
    {
        String msg = message.replace("你", "我").replace("吗", "");
        WebSocketUsers.sendMessageToUserByText(session, msg);
    }
}

3、SemaphoreUtils

package com.ruoyi.framework.websocket;

import java.util.concurrent.Semaphore;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 信号量相关处理
 *
 * @author ruoyi
 */
public class SemaphoreUtils
{
    /**
     * SemaphoreUtils 日志控制器
     */
    private static final Logger LOGGER = LoggerFactory.getLogger(SemaphoreUtils.class);

    /**
     * 获取信号量
     *
     * @param semaphore
     * @return
     */
    public static boolean tryAcquire(Semaphore semaphore)
    {
        boolean flag = false;

        try
        {
            flag = semaphore.tryAcquire();
        }
        catch (Exception e)
        {
            LOGGER.error("获取信号量异常", e);
        }

        return flag;
    }

    /**
     * 释放信号量
     *
     * @param semaphore
     */
    public static void release(Semaphore semaphore)
    {

        try
        {
            semaphore.release();
        }
        catch (Exception e)
        {
            LOGGER.error("释放信号量异常", e);
        }
    }
}

4、WebSocketUsers

package com.ruoyi.framework.websocket;

import java.io.IOException;
import java.util.Collection;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import javax.websocket.Session;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * websocket 客户端用户集
 *
 * @author ruoyi
 */
public class WebSocketUsers
{
    /**
     * WebSocketUsers 日志控制器
     */
    private static final Logger LOGGER = LoggerFactory.getLogger(WebSocketUsers.class);

    /**
     * 用户集
     */
    private static Map<String, Session> USERS = new ConcurrentHashMap<String, Session>();

    /**
     * 存储用户
     *
     * @param key 唯一键
     * @param session 用户信息
     */
    public static void put(String key, Session session)
    {
        USERS.put(key, session);
    }

    /**
     * 移除用户
     *
     * @param session 用户信息
     *
     * @return 移除结果
     */
    public static boolean remove(Session session)
    {
        String key = null;
        boolean flag = USERS.containsValue(session);
        if (flag)
        {
            Set<Map.Entry<String, Session>> entries = USERS.entrySet();
            for (Map.Entry<String, Session> entry : entries)
            {
                Session value = entry.getValue();
                if (value.equals(session))
                {
                    key = entry.getKey();
                    break;
                }
            }
        }
        else
        {
            return true;
        }
        return remove(key);
    }

    /**
     * 移出用户
     *
     * @param key 键
     */
    public static boolean remove(String key)
    {
        LOGGER.info("\n 正在移出用户 - {}", key);
        Session remove = USERS.remove(key);
        if (remove != null)
        {
            boolean containsValue = USERS.containsValue(remove);
            LOGGER.info("\n 移出结果 - {}", containsValue ? "失败" : "成功");
            return containsValue;
        }
        else
        {
            return true;
        }
    }

    /**
     * 获取在线用户列表
     *
     * @return 返回用户集合
     */
    public static Map<String, Session> getUsers()
    {
        return USERS;
    }

    /**
     * 群发消息文本消息
     *
     * @param message 消息内容
     */
    public static void sendMessageToUsersByText(String message)
    {
        Collection<Session> values = USERS.values();
        for (Session value : values)
        {
            sendMessageToUserByText(value, message);
        }
    }

    /**
     * 发送文本消息
     *
     * @param userName 自己的用户名
     * @param message 消息内容
     */
    public static void sendMessageToUserByText(Session session, String message)
    {
        if (session != null)
        {
            try
            {
                session.getBasicRemote().sendText(message);
            }
            catch (IOException e)
            {
                LOGGER.error("\n[发送消息异常]", e);
            }
        }
        else
        {
            LOGGER.info("\n[你已离线]");
        }
    }
}

第三步：很关键，给websocket允许通过的权限，修改SecurityConfig文件的configure方法添加如下：

// websocket如果需要不登录也可以访问，需要在`SecurityConfig.java`中设置匿名访问
.antMatchers("/websocket/**").permitAll()

第四步：前端界面

<template>
  <div class="app-container home">
    <el-row :gutter="20">
      <el-col :sm="24" :lg="24">
        <h1>集成websocket测试</h1>
      </el-col>
    </el-row>
    <el-row :gutter="20">
      <el-col :sm="24" :lg="24">
        <div>
          <el-input v-model="url" type="text" style="width: 20%" /> &nbsp; &nbsp;
          <el-button @click="join" type="primary">连接</el-button>
          <el-button @click="exit" type="danger">断开</el-button>
          <br />
          <br />
          <el-input type="textarea" v-model="message" :rows="9" />
          <br />
          <br />
          <el-button type="info" @click="send">发送消息</el-button>
          <br />
          <br />
          <el-input type="textarea" v-model="text_content" :rows="9" /> 返回内容
          <br />
          <br />
        </div>
      </el-col>
    </el-row>
  </div>
</template>

<script>
export default {
  name: "Index",
  data() {
    return {
      url: "ws://127.0.0.1:8080/websocket/message",
      message: "",
      text_content: "",
      ws: null,
    };
  },
  methods: {
    join() {
      const wsuri = this.url;
      this.ws = new WebSocket(wsuri);
      const self = this;
      this.ws.onopen = function (event) {
        self.text_content = self.text_content + "已经打开连接!" + "\n";
      };
      this.ws.onmessage = function (event) {
        self.text_content = event.data + "\n";
      };
      this.ws.onclose = function (event) {
        self.text_content = self.text_content + "已经关闭连接!" + "\n";
      };
    },
    exit() {
      if (this.ws) {
        this.ws.close();
        this.ws = null;
      }
    },
    send() {
      if (this.ws) {
        this.ws.send(this.message);
      } else {
        alert("未连接到服务器");
      }
    },
  },
};
</script>

第五步：启动服务，测试