SpringBoot+WebSocket

1.导入依赖：

-- Spring Boot 2.x 使用 javax.websocket-- Spring Boot 3.x 使用 jakarta.websocket<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><exclusions><exclusion><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-tomcat</artifactId></exclusion></exclusions>
</dependency>

package com.js.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;/*** websocket配置类中*/
@Configuration
public class WebSocketConfig {/***  第一个配置是因为使用springboot内置容器，自己开发时需要配置，如果有独立的容器需要将其注释掉，* 也就意味着，如果将项目打成WAR包，部署到服务器，使用Tomcat启动时，需要注释掉ServerEndpointExporter配置；* @return*/@Beanpublic ServerEndpointExporter serverEndpointExporter() {return new ServerEndpointExporter();}/*** MyEndpointConfigure配置是因为我的需求需要，需要在websocket类中注入service层或者dao层的接口，* MyEndpointConfigure配置就是为了解决websocket无法注入的问题，如果没有需要可以不用配置* @return*/@Beanpublic MyEndpointConfigure newConfigure() {return new MyEndpointConfigure();}
}

package com.js.httpclenlient;
import com.hy.core.toolkit.util.CollectionUtil;
import org.springframework.stereotype.Component;import javax.annotation.Resource;
import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.stream.Collectors;/*** @author* @Description: WebSocket服务端代码，包含接收消息，推送消息等接口*/
@Component
@ServerEndpoint(value = "/socket/{archivecode}")
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 AtomicInteger online = new AtomicInteger();//concurrent包的线程安全Set，用来存放每个客户端对应的WebSocketServer对象的session。private static Map<Long, List<Session>> sessionPools = new HashMap<>();@Resourceprivate RemoteAccessClient remoteAccessClient;/*** 发送消息方法* @param sessions 客户端与socket建立的会话* @param message 消息* @throws IOException*/public void sendMessage(List<Session> sessions, String message) throws IOException{if(CollectionUtil.isNotEmpty(sessions)){sessions.stream().forEach(session-> {try {session.getBasicRemote().sendText(message);} catch (IOException e) {throw new RuntimeException(e);}});}}/*** 连接建立成功调用* @param session 客户端与socket建立的会话* @param archivecode 客户端的archivecode*/@OnOpenpublic void onOpen(Session session, @PathParam(value = "archivecode") Long archivecode){List<Session> sessions = sessionPools.get(archivecode);if(CollectionUtil.isNotEmpty(sessions)){sessions.add(session);sessionPools.put(archivecode, sessions);}else {List<Session> sessionList = new ArrayList<>();sessionList.add(session);sessionPools.put(archivecode, sessionList);}addOnlineCount();System.out.println(archivecode + "加入webSocket！当前人数为" + online);try {sendMessage( sessions, "欢迎" + archivecode + "加入连接！");} catch (IOException e) {throw new IllegalArgumentException("webSocket建立连接失败");}}/*** 关闭连接时调用* @param 关闭连接的客户端的session*/@OnClosepublic void onClose(Session session,@PathParam(value = "archivecode") String archivecode){Set<Long> sessionkey = sessionPools.keySet();for (Long key : sessionkey) {List<Session> sessions = sessionPools.get(key);boolean contains = sessions.contains(session);if(contains){sessions.remove(session);}}sessionPools.remove(archivecode);subOnlineCount();System.out.println(archivecode + "断开webSocket连接！当前人数为" + online);}/*** 收到客户端消息时触发（群发）* @param message* @throws IOException*/@OnMessagepublic void onMessage(String message) throws IOException{Set<Long> companyIds = sessionPools.keySet();for (Long companyid : companyIds) {List<Session> sessions = sessionPools.get(companyid);try {sendMessage(sessions, message);} catch(Exception e){e.printStackTrace();}}}/*** 发生错误时候* @param session* @param throwable*/@OnErrorpublic void onError(Session session, Throwable throwable){System.out.println("发生错误");throwable.printStackTrace();}/*** 给指定用户发送消息* @param archivecode 用户名* @param message 消息* @throws IOException*/public void sendInfo(Long archivecode, String message){List<Session> sessions = sessionPools.get(archivecode);try {sendMessage(sessions, message);}catch (Exception e){e.printStackTrace();}}/*** 根据用户名获取session会话对象* @param archivecode* @return*/public  List<Session> getSession(Long archivecode){List<Session> sessions = sessionPools.get(archivecode);return sessions;}public static void addOnlineCount(){online.incrementAndGet();}public static void subOnlineCount() {online.decrementAndGet();}}

package com.js.controller;import cn.hutool.json.JSONUtil;
import org.springframework.web.bind.annotation.*;import javax.annotation.Resource;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;/***  6.密集架报警信息实时更新获取*/@RequestMapping(value = "/denseRack/alarm", method = RequestMethod.POST)public void testSocket1(@RequestBody FilealertInformation dto) throws JsonProcessingException {Long archiveCompanyId = ThreadLocalUtil.getArchiveCompanyId();dto.setPageRefreshType("warning");String s = JSONUtil.toJsonStr(dto);webSocketServer.sendInfo(archiveCompanyId, s);}

测试发送

结果

Spring boot接入websocket时，启动报错

Spring Boot 2.x

javax.websocket.server.ServerContainer not available

Spring Boot 3.x

jakarta.websocket.server.ServerContainer not available

问题原因

1. 因为spring boot内带tomcat，tomcat中的websocket会有冲突。
解决方案:​ spring boot启动时排除tomcat依赖包即可<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId><exclusions><exclusion><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-tomcat</artifactId></exclusion></exclusions>
</dependency>

@SpringBootTest启动时没有启动servlet

解决方案:@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)

Spring Boot 与WebSocket API版本不对应

Spring Boot 2.x 使用 javax.websocketSpring Boot 3.x 使用 jakarta.websocket解决方案:<!-- SpringBoot3 引入以下依赖，并删除之前的 javax.websocket依赖 -->
<dependency><groupId>jakarta.websocket</groupId><artifactId>jakarta.websocket-api</artifactId><version>2.1.0</version>
</dependency>