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

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;
/**
 * @ Auther: 馬超偉
 * @ Date: 2020/06/16/14:35
 * @ Description: 開啟WebSocket支持
 */
@Configuration
public class WebSocketConfig {
 @Bean
 public ServerEndpointExporter serverEndpointExporter() {
  return new ServerEndpointExporter();
 }
}

package cc.mrbird.febs.external.webScoket;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.conditions.update.UpdateWrapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;
import org.springframework.stereotype.Service;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.time.LocalDateTime;
import java.util.List;
import java.util.concurrent.CopyOnWriteArraySet;

/**
 * Created with IntelliJ IDEA.
 * @ Auther: 馬超偉
 * @ Date: 2020/06/16/14:35
 * @ Description:
 * @ ServerEndpoint 注解是一個類層次的注解，它的功能主要是將目前的類定義成一個websocket服務(wù)器端,
 * 注解的值將被用于監(jiān)聽用戶連接的終端訪問URL地址,客戶端可以通過這個URL來連接到WebSocket服務(wù)器端
 */
@Component
@Slf4j
@Service
@ServerEndpoint("/api/websocket/{sid}")
public class WebSocketServer {
 //靜態(tài)變量，用來記錄當(dāng)前在線連接數(shù)。應(yīng)該把它設(shè)計成線程安全的。
 private static int onlineCount = 0;
 //concurrent包的線程安全Set，用來存放每個客戶端對應(yīng)的MyWebSocket對象。
 private static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<WebSocketServer>();

 //與某個客戶端的連接會話，需要通過它來給客戶端發(fā)送數(shù)據(jù)
 private Session session;

 //接收sid
 private String sid = "";

 /**
  * 連接建立成功調(diào)用的方法
  */
 @OnOpen
 public void onOpen(Session session, @PathParam("sid") String sid) {
  this.session = session;
  webSocketSet.add(this);  //加入set中
  this.sid = sid;
  addOnlineCount();   //在線數(shù)加1
  try {
   sendMessage("conn_success");
   log.info("有新窗口開始監(jiān)聽:" + sid + ",當(dāng)前在線人數(shù)為:" + getOnlineCount());
  } catch (IOException e) {
   log.error("websocket IO Exception");
  }
 }

 /**
  * 連接關(guān)閉調(diào)用的方法
  */
 @OnClose
 public void onClose() {
  webSocketSet.remove(this); //從set中刪除
  subOnlineCount();   //在線數(shù)減1
  //斷開連接情況下，更新主板占用情況為釋放
  log.info("釋放的sid為："+sid);
  //這里寫你 釋放的時候，要處理的業(yè)務(wù)
  log.info("有一連接關(guān)閉！當(dāng)前在線人數(shù)為" + getOnlineCount());

 }

 /**
  * 收到客戶端消息后調(diào)用的方法
  * @ Param message 客戶端發(fā)送過來的消息
  */
 @OnMessage
 public void onMessage(String message, Session session) {
  log.info("收到來自窗口" + sid + "的信息:" + message);
  //群發(fā)消息
  for (WebSocketServer item : webSocketSet) {
   try {
    item.sendMessage(message);
   } catch (IOException e) {
    e.printStackTrace();
   }
  }
 }

 /**
  * @ Param session
  * @ Param error
  */
 @OnError
 public void onError(Session session, Throwable error) {
  log.error("發(fā)生錯誤");
  error.printStackTrace();
 }

 /**
  * 實現(xiàn)服務(wù)器主動推送
  */
 public void sendMessage(String message) throws IOException {
  this.session.getBasicRemote().sendText(message);
 }

 /**
  * 群發(fā)自定義消息
  */
 public static void sendInfo(String message, @PathParam("sid") String sid) throws IOException {
  log.info("推送消息到窗口" + sid + "，推送內(nèi)容:" + message);

  for (WebSocketServer item : webSocketSet) {
   try {
    //這里可以設(shè)定只推送給這個sid的，為null則全部推送
    if (sid == null) {
//     item.sendMessage(message);
    } else if (item.sid.equals(sid)) {
     item.sendMessage(message);
    }
   } catch (IOException e) {
    continue;
   }
  }
 }

 public static synchronized int getOnlineCount() {
  return onlineCount;
 }

 public static synchronized void addOnlineCount() {
  WebSocketServer.onlineCount++;
 }

 public static synchronized void subOnlineCount() {
  WebSocketServer.onlineCount--;
 }

 public static CopyOnWriteArraySet<WebSocketServer> getWebSocketSet() {
  return webSocketSet;
 }
}

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.servlet.ModelAndView;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

/**
 * Created with IntelliJ IDEA.
 *
 * @ Auther: 馬超偉
 * @ Date: 2020/06/16/14:38
 * @ Description:
 */
@Controller("web_Scoket_system")
@RequestMapping("/api/socket")
public class SystemController {
 //頁面請求
 @GetMapping("/index/{userId}")
 public ModelAndView socket(@PathVariable String userId) {
  ModelAndView mav = new ModelAndView("/socket1");
  mav.addObject("userId", userId);
  return mav;
 }

 //推送數(shù)據(jù)接口
 @ResponseBody
 @RequestMapping("/socket/push/{cid}")
 public Map pushToWeb(@PathVariable String cid, String message) {
  Map<String,Object> result = new HashMap<>();
  try {
   WebSocketServer.sendInfo(message, cid);
   result.put("code", cid);
   result.put("msg", message);
  } catch (IOException e) {
   e.printStackTrace();
  }
  return result;
 }
}

<!DOCTYPE html>
<html>

	<head>
		<meta charset="utf-8">
		<title>Java后端WebSocket的Tomcat實現(xiàn)</title>
		<script type="text/javascript" src="js/jquery.min.js"></script>
	</head>

	<body>
		<div id="main" style="width: 1200px;height:800px;"></div>
		Welcome<br/><input id="text" type="text" />
		<button onclick="send()">發(fā)送消息</button>
		<hr/>
		<button onclick="closeWebSocket()">關(guān)閉WebSocket連接</button>
		<hr/>
		<div id="message"></div>
	</body>
	<script type="text/javascript">
		var websocket = null;
		//判斷當(dāng)前瀏覽器是否支持WebSocket
		if('WebSocket' in window) {
			//改成你的地址
			websocket = new WebSocket("ws://192.168.100.196:8082/api/websocket/100");
		} else {
			alert('當(dāng)前瀏覽器 Not support websocket')
		}

		//連接發(fā)生錯誤的回調(diào)方法
		websocket.onerror = function() {
			setMessageInnerHTML("WebSocket連接發(fā)生錯誤");
		};

		//連接成功建立的回調(diào)方法
		websocket.onopen = function() {
			setMessageInnerHTML("WebSocket連接成功");
		}
		var U01data, Uidata, Usdata
		//接收到消息的回調(diào)方法
		websocket.onmessage = function(event) {
			console.log(event);
			setMessageInnerHTML(event);
			setechart()
		}

		//連接關(guān)閉的回調(diào)方法
		websocket.onclose = function() {
			setMessageInnerHTML("WebSocket連接關(guān)閉");
		}

		//監(jiān)聽窗口關(guān)閉事件，當(dāng)窗口關(guān)閉時，主動去關(guān)閉websocket連接，防止連接還沒斷開就關(guān)閉窗口，server端會拋異常。
		window.onbeforeunload = function() {
			closeWebSocket();
		}

		//將消息顯示在網(wǎng)頁上
		function setMessageInnerHTML(innerHTML) {
			document.getElementById('message').innerHTML += innerHTML + '<br/>';
		}

		//關(guān)閉WebSocket連接
		function closeWebSocket() {
			websocket.close();
		}

		//發(fā)送消息
		function send() {
			var message = document.getElementById('text').value;
			websocket.send('{"msg":"' + message + '"}');
			setMessageInnerHTML(message + "&#13;");
		}
	</script>

</html>