前言

websockt

什么是websockt？

WebSocket是一種在Web應(yīng)用程序中實(shí)現(xiàn)實(shí)時雙向通信的技術(shù)。Web應(yīng)用程序通常是基于HTTP協(xié)議的，HTTP是一種請求/響應(yīng)式的協(xié)議，客戶端發(fā)起請求，服務(wù)器響應(yīng)請求并發(fā)送響應(yīng)，客戶端收到響應(yīng)后關(guān)閉連接。這意味著，如果客戶端需要不斷地從服務(wù)器獲取更新，它必須定期發(fā)送請求以檢查更新，這將導(dǎo)致大量的網(wǎng)絡(luò)流量和不必要的服務(wù)器負(fù)載。

WebSocket通過在客戶端和服務(wù)器之間創(chuàng)建持久化連接，允許雙向?qū)崟r通信。這意味著服務(wù)器可以主動向客戶端推送更新，而不必等待客戶端不停地請求。WebSocket連接始于HTTP握手，然后升級到WebSocket協(xié)議。在升級過程中，客戶端和服務(wù)器之間的數(shù)據(jù)傳輸方式從HTTP變成了WebSocket協(xié)議，這樣可以降低傳輸數(shù)據(jù)的延遲和提高傳輸數(shù)據(jù)的可靠性。

在WebSocket協(xié)議中，數(shù)據(jù)是以幀的形式傳輸?shù)?#xff0c;幀包括數(shù)據(jù)頭和數(shù)據(jù)體兩個部分。數(shù)據(jù)頭指示數(shù)據(jù)類型，數(shù)據(jù)傳輸?shù)姆较虻刃畔?#xff0c;數(shù)據(jù)體則包括實(shí)際傳輸?shù)臄?shù)據(jù)。WebSocket支持文本類型和二進(jìn)制類型的數(shù)據(jù)。文本類型的數(shù)據(jù)使用UTF-8編碼，而二進(jìn)制類型的數(shù)據(jù)可以包括任何二進(jìn)制數(shù)據(jù)，如圖像、音頻、視頻等。

WebSockets是非常適合實(shí)時通信的技術(shù)。它可以用于在線游戲、在線聊天、推送通知、實(shí)時監(jiān)控等，并且比傳統(tǒng)的輪詢技術(shù)更加高效和可靠。對于現(xiàn)代Web應(yīng)用程序而言，WebSockets已經(jīng)成為不可或缺的技術(shù)之一。

websockt和Socket區(qū)別

區(qū)別	WebSocket	Socket
應(yīng)用層協(xié)議	基于HTTP協(xié)議，升級為WebSocket協(xié)議	沒有明確的應(yīng)用層協(xié)議，常用于傳輸TCP或UDP數(shù)據(jù)
傳輸數(shù)據(jù)類型	支持文本和二進(jìn)制類型的數(shù)據(jù)	通常用于傳輸二進(jìn)制數(shù)據(jù)，如圖片、視頻等
客戶端和服務(wù)器通信	支持實(shí)時雙向通信	支持雙向通信，但通常需要進(jìn)行輪詢或長連接
傳輸效率	比傳統(tǒng)的輪詢技術(shù)更加高效和可靠，不會頻繁請求服務(wù)器	傳輸效率較低，需要進(jìn)行輪詢或者長連接來保持連接，會頻繁請求服務(wù)器
應(yīng)用場景	適用于實(shí)時通信，如在線游戲、在線聊天、推送通知、實(shí)時監(jiān)控等	適用于需要傳輸大量二進(jìn)制數(shù)據(jù)的場景，如文件傳輸、圖片處理等

代碼部分

引入maven依賴

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

說明：默認(rèn)版本為1.5.10RELEASE，可自定義版本，加入“<version">"”標(biāo)簽即可
常量類

package com.dmsdbj.itoo.utils;
public class Constant {//webSocket相關(guān)配置//鏈接地址public static String WEBSOCKETPATHPERFIX = "/ws-push";public static String WEBSOCKETPATH = "/endpointWisely";//消息代理路徑public static String WEBSOCKETBROADCASTPATH = "/topic";//前端發(fā)送給服務(wù)端請求地址public static final String FORETOSERVERPATH = "/welcome";//服務(wù)端生產(chǎn)地址,客戶端訂閱此地址以接收服務(wù)端生產(chǎn)的消息public static final String PRODUCERPATH = "/topic/getResponse";//點(diǎn)對點(diǎn)消息推送地址前綴public static final String P2PPUSHBASEPATH = "/user";//點(diǎn)對點(diǎn)消息推送地址后綴,最后的地址為/user/用戶識別碼/msgpublic static final String P2PPUSHPATH = "/msg";
}

接收前端消息實(shí)體

package com.dmsdbj.itoo.vo;
public class WiselyMessage {private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}
}

后臺發(fā)送消息實(shí)體

package com.dmsdbj.itoo.vo;public class WiselyResponse {private String responseMessage;public WiselyResponse(String responseMessage){this.responseMessage = responseMessage;}public String getResponseMessage() {return responseMessage;}public void setResponseMessage(String responseMessage) {this.responseMessage = responseMessage;}
}

配置websocket

package com.dmsdbj.itoo.config;import com.dmsdbj.itoo.utils.Constant;
import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.AbstractWebSocketMessageBrokerConfigurer;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
@Configuration
// @EnableWebSocketMessageBroker注解用于開啟使用STOMP協(xié)議來傳輸基于代理（MessageBroker）的消息，這時候控制器（controller）
// 開始支持@MessageMapping,就像是使用@requestMapping一樣。
@EnableWebSocketMessageBroker
public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {@Overridepublic void registerStompEndpoints(StompEndpointRegistry stompEndpointRegistry) {//注冊一個Stomp的節(jié)點(diǎn)（endpoint）,并指定使用SockJS協(xié)議。stompEndpointRegistry.addEndpoint(Constant.WEBSOCKETPATH).withSockJS();}@Overridepublic void configureMessageBroker(MessageBrokerRegistry registry) {//服務(wù)端發(fā)送消息給客戶端的域,多個用逗號隔開registry.enableSimpleBroker(Constant.WEBSOCKETBROADCASTPATH, Constant.P2PPUSHBASEPATH);//定義一對一推送的時候前綴registry.setUserDestinationPrefix(Constant.P2PPUSHBASEPATH);//定義websoket前綴registry.setApplicationDestinationPrefixes(Constant.WEBSOCKETPATHPERFIX);}
}

采用JPA方法進(jìn)行操作數(shù)據(jù)庫DAO層

package com.dmsdbj.itoo.repository;
import com.dmsdbj.itoo.entity.TbUser;
import org.springframework.data.jpa.repository.JpaRepository;
public interface TbUseRepository extends JpaRepository<TbUser,Long> {}

sql語句

CREATE TABLE `tb_user` (`id` bigint(20) NOT NULL AUTO_INCREMENT,`username` varchar(50) DEFAULT NULL COMMENT '用戶名',`password` varchar(32) DEFAULT NULL COMMENT '密碼，加密存儲',`phone` varchar(20) DEFAULT NULL COMMENT '注冊手機(jī)號',`email` varchar(50) DEFAULT NULL COMMENT '注冊郵箱',`created` datetime DEFAULT NULL,`updated` datetime DEFAULT NULL,PRIMARY KEY (`id`),UNIQUE KEY `username` (`username`) USING BTREE,UNIQUE KEY `phone` (`phone`) USING BTREE,UNIQUE KEY `email` (`email`) USING BTREE
) ENGINE=InnoDB AUTO_INCREMENT=18333611875 DEFAULT CHARSET=utf8 COMMENT='用戶表';

TbUser實(shí)體類

package com.dmsdbj.itoo.entity;
import lombok.Data;
import javax.persistence.Entity;
import javax.persistence.Id;
import java.io.Serializable;
@Entity
@Data
public class TbUser implements Serializable {@Idprivate Long id;private String username;private String password;private String phone;public Long getId() {return id;}public void setId(Long id) {this.id = id;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}public String getPassword() {return password;}public void setPassword(String password) {this.password = password;}public String getPhone() {return phone;}public void setPhone(String phone) {this.phone = phone;}
}

Service實(shí)現(xiàn)類

@Service
public class TbUseServiceImpl implements TbUseService {@AutowiredTbUseRepository repository;/*** 從數(shù)據(jù)庫查詢用戶，給訂閱者發(fā)送消息* @return*/@Overridepublic List<Long> send2Users() {return repository.findAll().stream().map(s -> s.getId()).collect(Collectors.toList());}
}

Service接口類

public interface TbUseService {List<Long> send2Users();
}

Fa?ade實(shí)現(xiàn)類

@Service
public class TbUseFacadeImpl implements TbUseFacade {@AutowiredTbUseService tbUseService;@Overridepublic List<Long> send2Users() {return tbUseService.send2Users();}
}

Fa?ade接口類

public interface TbUseFacade {
List<Long> send2Users();
}

Controller類

@Controller
public class SendInfoController {@ReferenceTbUseFacade tbUseFacade;@Autowiredprivate SimpMessagingTemplate template;@ResourceWebSocketService webSocketService;@MessageMapping(Constant.FORETOSERVERPATH)//@MessageMapping和@RequestMapping功能類似，用于設(shè)置URL映射地址，瀏覽器向服務(wù)器發(fā)起請求，需要通過該地址。
//    @SendTo(Constant.PRODUCERPATH)//如果服務(wù)器接受到了消息，就會對訂閱了@SendTo括號中的地址傳送消息。public WiselyResponse say(WiselyMessage message) throws Exception {List<Long> userId = tbUseFacade.send2Users();userId.forEach(s->{template.convertAndSendToUser(s.toString(),Constant.P2PPUSHPATH, new WiselyResponse(message.getName()));});return null;}
}

前端頁面
sendws.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head><meta charset="UTF-8" /><title>Spring Boot+WebSocket+廣播式</title></head>
<body onload="disconnect()">
<noscript><h2 style="color: #ff0000">貌似你的瀏覽器不支持websocket</h2></noscript>
<div><div><button id="connect" onclick="connect();">連接</button><button id="disconnect" disabled="disabled" onclick="disconnect();">斷開連接</button></div><div id="conversationDiv"><label>輸入要發(fā)送的消息</label><input type="text" id="name" /><button id="sendName" onclick="sendName();">發(fā)送</button><p id="response"></p><p id="response1"></p></div>
</div>
<!--<script th:src="@{sockjs.min.js}"></script>
<script th:src="@{stomp.min.js}"></script>
<script th:src="@{jquery.js}"></script>-->
<script src="https://cdn.bootcss.com/sockjs-client/1.1.4/sockjs.min.js"></script>
<script src="https://cdn.bootcss.com/stomp.js/2.3.3/stomp.min.js"></script>
<script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>
<script th:inline="javascript">var stompClient = null;//此值有服務(wù)端傳遞給前端,實(shí)現(xiàn)方式?jīng)]有要求//var userId = [[${userId}]];var userId = 'd892bf12bf7d11e793b69c5c8e6f60fb';function setConnected(connected) {document.getElementById('connect').disabled = connected;document.getElementById('disconnect').disabled = !connected;document.getElementById('conversationDiv').style.visibility = connected ? 'visible' : 'hidden';$('#response').html();}function connect() {var socket = new SockJS('/endpointWisely'); //1連接SockJS的endpoint是“endpointWisely”，與后臺代碼中注冊的endpoint要一樣。stompClient = Stomp.over(socket);//2創(chuàng)建STOMP協(xié)議的webSocket客戶端。stompClient.connect({}, function(frame) {//3連接webSocket的服務(wù)端。setConnected(true);console.log('開始進(jìn)行連接Connected: ' + frame);});}function disconnect() {if (stompClient != null) {stompClient.disconnect();}setConnected(false);console.log("Disconnected");}function sendName() {var name = $('#name').val();console.log(name);//通過stompClient.send（）向地址為"/welcome"的服務(wù)器地址發(fā)起請求，與@MessageMapping里的地址對應(yīng)。因?yàn)槲覀兣渲昧藃egistry.setApplicationDestinationPrefixes(Constant.WEBSOCKETPATHPERFIX);所以需要增加前綴/ws-push/stompClient.send("/ws-push/welcome", {}, JSON.stringify({ 'name': name }));}
</script>
</body>
</html>

subws.html

<!DOCTYPE html>
<html xmlns:th="http://www.thymeleaf.org">
<head><meta charset="UTF-8" /><title>Spring Boot+WebSocket+廣播式</title></head>
<body onload="disconnect()">
<noscript><h2 style="color: #ff0000">貌似你的瀏覽器不支持websocket</h2></noscript>
<div><div><button id="connect" onclick="connect();">連接</button><button id="disconnect" disabled="disabled" onclick="disconnect();">斷開連接</button></div><div id="conversationDiv"><label>輸入你的userId</label><input type="text" id="userId" /><button id="subMsg" onclick="subMsg();">訂閱消息</button><p id="response"></p><p id="response1"></p></div>
</div>
<!--<script th:src="@{sockjs.min.js}"></script>
<script th:src="@{stomp.min.js}"></script>
<script th:src="@{jquery.js}"></script>-->
<script src="https://cdn.bootcss.com/sockjs-client/1.1.4/sockjs.min.js"></script>
<script src="https://cdn.bootcss.com/stomp.js/2.3.3/stomp.min.js"></script>
<script src="https://cdn.bootcss.com/jquery/3.2.1/jquery.min.js"></script>
<script th:inline="javascript">var stompClient = null;//此值有服務(wù)端傳遞給前端,實(shí)現(xiàn)方式?jīng)]有要求//var userId = [[${userId}]];function setConnected(connected) {document.getElementById('connect').disabled = connected;document.getElementById('disconnect').disabled = !connected;document.getElementById('conversationDiv').style.visibility = connected ? 'visible' : 'hidden';$('#response').html();}function connect() {var socket = new SockJS('/endpointWisely'); //1連接SockJS的endpoint是“endpointWisely”，與后臺代碼中注冊的endpoint要一樣。stompClient = Stomp.over(socket);//2創(chuàng)建STOMP協(xié)議的webSocket客戶端。stompClient.connect({}, function(frame) {//3連接webSocket的服務(wù)端。setConnected(true);console.log('開始進(jìn)行連接Connected: ' + frame);//4通過stompClient.subscribe（）訂閱服務(wù)器的目標(biāo)是'/topic/getResponse'發(fā)送過來的地址，與@SendTo中的地址對應(yīng)。/*stompClient.subscribe('/topic/getResponse', function(respnose){showResponse(JSON.parse(respnose.body).responseMessage);});*/});}function subMsg() {var userId = $('#userId').val();console.log(userId);$.ajax({type: 'GET',url: '/user/insert?userId='+userId,//data: userId,success: function (data) {console.log(data);//4通過stompClient.subscribe（）訂閱服務(wù)器的目標(biāo)是'/user/' + userId + '/msg'接收一對一的推送消息,其中userId由服務(wù)端傳遞過來,用于表示唯一的用戶,通過此值將消息精確推送給一個用戶stompClient.subscribe('/user/' + userId + '/msg', function(respnose){console.log(respnose);showResponse1(JSON.parse(respnose.body).responseMessage);});}});}function disconnect() {if (stompClient != null) {stompClient.disconnect();}setConnected(false);console.log("Disconnected");}function showResponse1(message) {var response = $("#response1");response.html(message);}
</script>
</body>
</html>

實(shí)戰(zhàn)應(yīng)用

①啟動springboot-dubbo-service的主啟動類“SpringbootDubboServiceApplication”
②啟動springboot-dubbo-web的主啟動類“SpringbootDubboWebApplication”
③訪問
http://localhost:9000/sendws 發(fā)送消息方
http://localhost:9000/subws 訂閱消息方
④分別進(jìn)行連接操作
訂閱方輸入訂閱方的連接賬號userid，后期就可以接收發(fā)送端發(fā)送的消息
連接后的結(jié)果展示