springboot集成websocket全全全！！！-编程知识

一、界面展示

二、前置了解

1.什么是websocket

WebSocket是一种在单个TCP连接上进行全双工通信的持久化协议。
全双工协议就是客户端可以给我们服务器发数据服务器也可以主动给客户端发数据。

2.为什么有了http协议还要websocket 协议

http协议是一种无状态，非持久化的单全双工应用层协议。
主要用于一问一答的方式交付信息，即客户端发送请求，服务器返回响应。这种模式适合于获取数据或者提交数据的场景。

所以http协议中，服务器无法主动给客户端发送数据，导致出现服务器数据状态发生改变，客户端无法感知。

针对上面的问题，http 勉强可以通过定时轮询和长轮询解决问题。

定时轮询：客户端不断地定时请求服务器, 询问数据状态变更的情况。
定时轮询的弊端：存在延时，浪费服务器资源和带宽，存在大量无效请求。

长轮询：拉长请求时间，客户端发送请求后，服务器在没有新数据时不会立即响应，而是等到有新数据时才返回响应。这种方法可以减少无效的请求，
长轮询的弊端：仍然需要频繁地建立和断开连接，且服务器需要维护未完成的请求，这可能会占用大量的服务器资源。

承上启下所有最后我们websocket应运而生，它就是为了解决这个问题而设计的。
WebSocket协议可以实现全双工通信，即客户端和服务器可以在任何时候相互主动发送数据。此外，一旦WebSocket连接建立，客户端和服务器之间的连接将保持活动状态，直到被任何一方关闭。

三、附集成代码

1.引入pom依赖

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

2.使用@ServerEndpoint创建WebSocket Endpoint

package com.ruoyi.framework.websocket;import com.ruoyi.common.core.domain.model.LoginUser;
import com.ruoyi.common.utils.StringUtils;
import com.ruoyi.framework.config.WebSocketConfig;
import com.ruoyi.framework.web.service.TokenService;
import org.slf4j.Logger;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.concurrent.atomic.AtomicLong;import org.slf4j.LoggerFactory;/*** @author qujingye* @Classname WebSocketServer* @Description  虽然@Component默认是单例模式的，但springboot还是会为每个websocket连接初始化一个bean* @Date 2023/12/19 16:11*/
@Component
@ServerEndpoint(value = "/websocket/message", configurator = WebSocketConfig.class)
public class WebSocketServer {private static TokenService tokenService;@Autowiredprivate void setOriginMessageSender(TokenService tokenService) {WebSocketServer.tokenService = tokenService;}/*** WebSocketServer 日志控制器*/private static final Logger LOGGER = LoggerFactory.getLogger(WebSocketServer.class);private final static ConcurrentHashMap<Long, CopyOnWriteArrayList<Session>> sessionPool = new ConcurrentHashMap<>();private final static AtomicLong atomicLong = new AtomicLong(0L);/*** 连接建立成功调用的方法*/@OnOpenpublic void onOpen(Session session) throws Exception {Long userId = parseUserId(session);System.out.println(userId);LOGGER.info("[WebSocket] 有新的连接, 当前用户id: {}", userId);if (userId == null) {return;}CopyOnWriteArrayList<Session> sessions = sessionPool.get(userId);//不存在其他人登陆if (null == sessions) {sessions = new CopyOnWriteArrayList<>();}sessions.add(session);sessionPool.put(userId, sessions);atomicLong.getAndIncrement();LOGGER.info("[WebSocket] 有新的连接, 当前连接数: {}", atomicLong.get());}/*** 连接关闭时处理*/@OnClosepublic void onClose(Session session) {Long userId = parseUserId(session);if (userId == null) {return;}CopyOnWriteArrayList<Session> sessions = sessionPool.remove(userId);CopyOnWriteArrayList<Session> newSessions = new CopyOnWriteArrayList<>();for (Session s : sessions) {if (!s.getId().equals(session.getId())) {newSessions.add(s);}}sessionPool.put(userId, newSessions);atomicLong.getAndDecrement();LOGGER.info("[WebSocket] 连接断开, 当前连接数: {}", atomicLong.get());}/*** 抛出异常时处理*/@OnErrorpublic void onError(Session session, Throwable exception) throws Exception {LOGGER.error("用户错误:,原因:" + exception.getMessage());}/*** 服务器接收到客户端消息时调用的方法*/@OnMessagepublic void onMessage(String message, Session session) {//把收到的消息发回去session.getAsyncRemote().sendText(message);LOGGER.info("message: {}", message);}/*** 给该用户id的全部发送消息*/public void sendMessage(Long userId, String message) {CopyOnWriteArrayList<Session> sessions = sessionPool.get(userId);if (null == sessions || sessions.size() == 0) {return;}sessions.forEach(s -> s.getAsyncRemote().sendText(message));}/*** 获取用户id*/private Long parseUserId(Session session) {String token = (String) session.getUserProperties().get(WebSocketConfig.WEBSOCKET_PROTOCOL);if (StringUtils.isNotEmpty(token)) {LoginUser loginUser = tokenService.getLoginUserByToken(token);if (loginUser != null) {return loginUser.getUserId();}}return null;}
}

3.定义WebSocketConfig

注入ServerEndpointExporter来自动注册端点

package com.ruoyi.framework.config;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.socket.server.standard.ServerEndpointExporter;import javax.websocket.HandshakeResponse;
import javax.websocket.server.HandshakeRequest;
import javax.websocket.server.ServerEndpointConfig;
import java.util.List;
import java.util.Map;/*** @author qujingye* @Classname WebSocketConfig* @Description 继承服务器断点配置类* @Date 2023/12/19 16:08*/
@Configuration
public class WebSocketConfig extends ServerEndpointConfig.Configurator {/*** WebSocket的协议头*/public final static String WEBSOCKET_PROTOCOL = "Sec-Websocket-Protocol";/*** 注入ServerEndpointExporter，这个Bean会自动注册使用了@ServerEndpoint注解声明的WebSocket Endpoint。*/@Beanpublic ServerEndpointExporter serverEndpointExporter() {return new ServerEndpointExporter();}/*** 建立握手时，连接前的操作*/@Overridepublic void modifyHandshake(ServerEndpointConfig sec, HandshakeRequest request, HandshakeResponse response) {// 这个用户属性userProperties 可以通过 session.getUserProperties()获取final Map<String, Object> userProperties = sec.getUserProperties();Map<String, List<String>> headers = request.getHeaders();List<String> protocol = headers.get(WEBSOCKET_PROTOCOL);// 存放自己想要的header信息if (protocol != null) {userProperties.put(WEBSOCKET_PROTOCOL, protocol.get(0));}}/*** 创建端点实例,也就是被@ServerEndpoint所标注的对象*/@Overridepublic <T> T getEndpointInstance(Class<T> clazz) throws InstantiationException {return super.getEndpointInstance(clazz);}}

4.定义过滤器设置响应头

package com.ruoyi.framework.security.filter;import com.ruoyi.common.utils.StringUtils;
import com.ruoyi.framework.config.WebSocketConfig;
import org.springframework.core.annotation.Order;
import org.springframework.stereotype.Component;import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;/*** FileName:     com.admin.security.filter WebsocketFilter* Date:         2023/8/1 16:42** @author Messylee*/
@Order(1)
@Component
@WebFilter(filterName = "WebsocketFilter", urlPatterns = "/ws/**")
public class WebsocketFilter implements Filter {@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {HttpServletResponse response = (HttpServletResponse) servletResponse;HttpServletRequest headers = (HttpServletRequest) servletRequest;String token = headers.getHeader(WebSocketConfig.WEBSOCKET_PROTOCOL);if (StringUtils.isNotEmpty(token)){response.setHeader(WebSocketConfig.WEBSOCKET_PROTOCOL, token);}filterChain.doFilter(servletRequest, servletResponse);}}

5.vue前端界面代码

<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><el-button @click="resetForm" type="success">重置</el-button><br /><br /><el-input type="textarea" v-model="message" :rows="9" /><br /><br /><el-button type="success" @click="send">发送消息</el-button><br /><br />返回内容<el-input type="textarea" v-model="text_content" :rows="9" /><br /><br /></div></el-col></el-row></div>
</template><script>
import { getToken } from "@/utils/auth";export default {name: "Index",data() {return {url: "ws://127.0.0.1:8080/websocket/message",message: "",text_content: "",ws: null,headers: {Authorization: "Bearer " + getToken(),},};},methods: {join() {const wsuri = this.url;// this.ws = new WebSocket(wsuri);this.ws = new WebSocket(wsuri, [getToken()]);const self = this;// 连接成功后调用this.ws.onopen = function (event) {self.text_content = self.text_content + "WebSocket连接成功!" + "\n";};this.ws.onerror = function (event) {self.text_content = self.text_content + "WebSocket连接发生错误!" + "\n";};// 接收后端消息this.ws.onmessage = function (event) {self.text_content = self.text_content + event.data + "\n";};// 关闭连接时调用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");}},//重置resetForm() {this.message = "";this.text_content = "";},},
};
</script>