1.spring boot 引入依赖
<dependency><!-- websocket --><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-websocket</artifactId></dependency>2.添加配置类
java">import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;/*** @Description: 开启WebSocket支持*/
@Configuration
public class WebSocketConfig {@Beanpublic ServerEndpointExporter serverEndpointExporter() {return new ServerEndpointExporter();}
}3.构建websocketserver
java">import lombok.Getter;
import lombok.extern.slf4j.Slf4j;import java.util.concurrent.CopyOnWriteArraySet;
import java.util.stream.Collectors;/*** @version 1.0* @description 存放websocket连接的集合* @date 2025/1/20 10:46**/
@Slf4j
public class WebSockeServerLocalCache {@Getterprivate final static CopyOnWriteArraySet<WebSocketServer> webSocketSet = new CopyOnWriteArraySet<>();/*** 将指定的键添加到集合中。** @param webSocketServer 要添加到集合中的键* @return 添加成功，则返回 true；否则返回 false*/public static void save(WebSocketServer webSocketServer) {log.info("添加到缓存中:{}", webSocketServer);webSocketSet.add(webSocketServer);}/*** 判断集合中是否不包含指定的键。** @param webSocketServer 要删除的实例*/public static boolean remove(WebSocketServer webSocketServer) {return webSocketSet.remove(webSocketServer);}/**** 根据sid获取websocket连接* @param sid* @return*/public static CopyOnWriteArraySet<WebSocketServer> get(String sid) {return webSocketSet.stream().filter(webSocketServer -> webSocketServer.getSid().equals(sid)).collect(Collectors.toCollection(CopyOnWriteArraySet::new));}
}
java">
import lombok.Getter;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;/*** @version 1.0* @description WebSocketServer实例* @date 2025/1/20 10:46**/
@Getter
@Slf4j
@Service
@ServerEndpoint(value = "/sysoperation/alarmWebSocketData/{sid}", encoders = {CustomEncoder.class})
public class WebSocketServer {// 静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。private static int onlineCount = 0;//与某个客户端的连接会话，需要通过它来给客户端发送数据private Session session;//接收sidprivate String sid = "";/*** 连接建立成功调用的方法*/@OnOpenpublic void onOpen(Session session, @PathParam("sid") String sid) {this.session = session;this.sid = sid;//在线数加1addOnlineCount();//保存实例到set中WebSockeServerLocalCache.save(this);sendMessage("conn_success");log.info("有新窗口开始监听sid{},当前在线人数为:{}",sid, getOnlineCount());}/*** 连接关闭调用的方法*/@OnClosepublic void onClose() {//从set中删除
// webSocketSet.remove(this);boolean remove = WebSockeServerLocalCache.remove(this);log.info("移除的sid为:{},结果为{}",sid,remove);//在线数减1subOnlineCount();//断开连接情况下，更新占用情况为释放log.info("释放的sid为：" + sid);//这里写你 释放的时候，要处理的业务 todolog.info("有一连接关闭！当前在线人数为" + getOnlineCount());// 连接关闭 停止任务}/*** 收到客户端消息后调用的方法** @Param message 客户端发送过来的消息*/@OnMessagepublic void onMessage(String message, Session session) {log.info("收到来自窗口sid{},的信息:{}",sid, message);//群发消息WebSockeServerLocalCache.get(sid).forEach(webSocketServer -> {webSocketServer.sendMessage(message);});}/*** @Param session* @Param error*/@OnErrorpublic void onError(Session session, Throwable error) {log.error("发生错误");error.printStackTrace();}/*** 实现服务器主动推送*/public void sendMessage(Object message) {try {this.session.getBasicRemote().sendObject(message);} catch (IOException | EncodeException e) {log.error("推送消息发生异常:" + e.getMessage());}}/*** 群发自定义消息*/public static void sendInfo(String message, @PathParam("sid") String sid) throws IOException {log.info("推送消息到窗口" + sid + "，推送内容:" + message);CopyOnWriteArraySet<WebSocketServer> webSocketServers = WebSockeServerLocalCache.get(sid);for (WebSocketServer item : webSocketServers) {//这里可以设定只推送给这个sid的，为null则全部推送if (sid == null) {// item.sendMessage(message);} else if (item.sid.equals(sid)) {item.sendMessage(message);}}}public static synchronized int getOnlineCount() {return onlineCount;}public static synchronized void addOnlineCount() {WebSocketServer.onlineCount++;}public static synchronized void subOnlineCount() {WebSocketServer.onlineCount--;}}
其他公共类
java">@Data
public class AlarmInfoDTO implements Serializable {private String alarmType;private String time;private String alarmContent;private String alarmTitle;private String alarmReceivePerson;private String realAlarm="Real";private AlarmInfoExtDataDTO extData;
}@Data
public class AlarmInfoExtDataDTO implements Serializable {private Long taskId;private String deviceId;private String imagePath;private String storagePath;private String motorVehicleId;private String plateNo;private String plateColor;private String plateClass;private String vehicleClass;private String vehicleBrand;private String deviceName;private String latitude;private String longitude;private String areaName;}import javax.websocket.EncodeException;
import javax.websocket.Encoder;
import javax.websocket.EndpointConfig;
import com.fasterxml.jackson.databind.ObjectMapper;public class CustomEncoder implements Encoder.Text<Object> {private static final ObjectMapper objectMapper = new ObjectMapper();@Overridepublic String encode(Object object) throws EncodeException {try {return objectMapper.writeValueAsString(object);} catch (Exception e) {throw new EncodeException(object, "Error encoding object", e);}}@Overridepublic void init(EndpointConfig config) {// 初始化时的逻辑（可选）}@Overridepublic void destroy() {// 销毁时的逻辑（可选）}
}
前端html测试
<!DOCTYPE html>
<html><head><meta charset="utf-8"><title>Java后端WebSocket的Tomcat实现</title>
</head><body>
<h1>Welcome</h1>
<br/><input id="text" type="text" />
<button onclick="send()">发送消息</button>
<hr/>
<button onclick="closeWebSocket()">关闭WebSocket连接</button>
<hr/>
<div id="message"></div>
</body>
<script type="text/javascript">var websocket = null;//判断当前浏览器是否支持WebSocketif('WebSocket' in window) {//改成你的地址 ws://127.0.0.1:10242/sysoperation/alarmWebSocketData/{sid} 用taskid 当作sidwebsocket = new WebSocket("ws://127.0.0.1:10242/sysoperation/alarmWebSocketData/48");} else {alert('当前浏览器 Not support websocket')}//连接发生错误的回调方法websocket.onerror = function() {setMessageInnerHTML("WebSocket连接发生错误");};//连接成功建立的回调方法websocket.onopen = function() {setMessageInnerHTML("WebSocket连接成功");}var U01data, Uidata, Usdata//接收到消息的回调方法websocket.onmessage = function(event) {console.log(event);setMessageInnerHTML(event);//setechart()}//连接关闭的回调方法websocket.onclose = function() {setMessageInnerHTML("WebSocket连接关闭");}//监听窗口关闭事件，当窗口关闭时，主动去关闭websocket连接，防止连接还没断开就关闭窗口，server端会抛异常。window.onbeforeunload = function() {closeWebSocket();}//将消息显示在网页上function setMessageInnerHTML(innerHTML) {document.getElementById('message').innerHTML += innerHTML + '<br/>';}//关闭WebSocket连接function closeWebSocket() {websocket.close();}//发送消息function send() {var message = document.getElementById('text').value;websocket.send('{"msg":"' + message + '"}');setMessageInnerHTML(message + " ");}
</script></html>
