SpringBoot的Web開發之WebSocket(廣播式)筆記總結

2020-10-25 13:00:29

戰鬥前準備:新建Spring Boot專案選擇Thymeleaf和WebSocket依賴

1.設定WebSocket

設定WebSocket.需要在設定類上使用@EnableWebSocketMessageBroker開啟WebSocket支援,並實現WebSocketMessageBrokerConfigurer介面,重寫方法來設定WebSocket

(SpringBoot顛覆者裡是繼承AbstractWebSocketMessageBrokerConfigurer 類,但是那個類已經過時了)

import org.springframework.context.annotation.Configuration;
import org.springframework.messaging.simp.config.MessageBrokerRegistry;
import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;
import org.springframework.web.socket.config.annotation.WebSocketMessageBrokerConfigurer;
/**
 * 第一步,設定WebSocket.需要在設定類上使用@EnableWebSocketMessageBroker開啟WebSocket支援
 * 並實現WebSocketMessageBrokerConfigurer介面
 * 重寫方法來設定WebSocket
 */
@Configuration
//通過@EnableWebSocketMessageBroker註解開啟使用STOMP協定在傳輸基於代理(message broker)的訊息
@EnableWebSocketMessageBroker
public class WebSocketConfig implements WebSocketMessageBrokerConfigurer {
    //註冊STOMP協定的節點(endpoint),並對映指定的URL
    public void registerStompEndpoints(StompEndpointRegistry registry){
        //註冊一個STOMP的endpoint,並指定使用SockJS協定
        registry.addEndpoint("/endpointWisely").withSockJS();
    }
    //設定訊息代理(Message Broker)
    public void configureMessageBroker(MessageBrokerRegistry registry){
        //廣播式設定一個/topic訊息代理
        registry.enableSimpleBroker("/topic");
    }
}

2.編寫瀏覽器向伺服器端傳送訊息(伺服器端用該類接收)

//瀏覽器向伺服器端傳送的訊息用此類接收
public class WiselyMessage {
    public String name;
    public String getName(){
        return  name;
    }
}

3. 編寫伺服器端向瀏覽器傳送訊息(伺服器端用該類傳送)

//伺服器端向瀏覽器傳送的此類的訊息
public class WiselyResponse {
    private String responseMessage;
    public WiselyResponse(String responseMessage){
        this.responseMessage = responseMessage;
    }

    public String getResponseMessage() {
        return responseMessage;
    }
}

4. 編寫一個Controller用於模擬傳送和接收

import org.springframework.messaging.handler.annotation.MessageMapping;
import org.springframework.messaging.handler.annotation.SendTo;
import org.springframework.stereotype.Controller;
import test.demo4.domain.WiselyMessage;
import test.demo4.domain.WiselyResponse;

@Controller
public class WsController {
    //當瀏覽器向伺服器端傳送請求時,通過@MessageMapping對映/welcome這個地址,類似於@RequestMapping
    @MessageMapping("/welcome")
    //當伺服器端有訊息時,會訂閱了@SendTo中的路徑的瀏覽器傳送訊息
    @SendTo("/topic/getResponse")
    public WiselyResponse say(WiselyMessage message)throws Exception{
        Thread.sleep(3000);
        return new WiselyResponse("Welcome   "+message.getName()+"  !");
    }
}

5.新增指令碼

將stomp.min.js、scokjs.min.js和jquery.js放置在src/main/resources/static下
找資源太難的話,當然已經為你們準備好啦!
連結失效的話後臺私信我哦!
連結:https://pan.baidu.com/s/1UsP-4w1OkTUiz_YvVgFlVQ
提取碼:9wpf
在這裡插入圖片描述

6. 編寫一個頁面來演示

<!DOCTYPE html>
<html lang="en" xmlns:th="http://www.thymeleaf.org">
<head>
  <meta charset="UTF-8">
  <title>Spring Boot+WebSoc+廣播式</title>
</head>
<body onload="disconnect()">
  <noscript><h2 style="color: #ff0000">貌似瀏覽器不支援WebSocket</h2></noscript>
<div>
  <div>
    <button id="connect" onclick="connect();">連線</button>
    <button id="disconnect" onclick="disconnect();">斷開連線</button>
  </div>
  <div id="conversationDiv">
    <label>輸入你的名字</label><input type="text" id="name"/>
    <button id="sendName" onclick="sendName();">傳送</button>
    <p id="response"></p>
  </div>
  <script th:src="@{sockjs.min.js}"></script>
  <script th:src="@{stomp.min.js}"></script>
  <script th:src="@{jquery.js}"></script>
  <script type="text/javascript">
    var stompClient  = null;
    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() {
      //連線SockJS的endpoint名稱為"/endpointWisely"
      var socket = new SockJS('/endpointWisely');
      //使用STOMP子協定的WebSocket使用者端
      stompClient = Stomp.over(socket);
      //連線WebSocket伺服器端
      stompClient.connect({},function (frame) {
        setConnected(true);
        console.log('Connected:'+frame);
        //通過stompClient.subscribe訂閱/topic/getResponse目標(destination)傳送訊息
        //這個是在控制器的@SendTo中定義的
        stompClient.subscribe('/topic/getResponse',function (response) {
          showResponse(JSON.parse(response.body).responseMessage);
        });
      });
    }

    function disconnect() {
      if (stompClient != null){
        stompClient.disconnect();
      }
      setConnected(false);
      console.log("Disconnected");
    }
    function sendName() {
      var name = $("#name").val();
      //通過stompClient.send向/welcome目標(destination)傳送訊息
      //這個是在控制器的@MessageMapping中定義的
      stompClient.send("/welcome",{},JSON.stringify({"name":name}));
    }
    function showResponse(message) {
      var response = $("#response");
      response.html(message);
    }
  </script>
</div>
</body>
</html>

7. 設定ViewController

為ws.html提供便捷的路徑對映
將所有/static/** 存取都對映到classpath:/static/ 目錄下

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.ViewControllerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {
	//為ws.html提供便捷的路徑對映
    public void addViewControllers(ViewControllerRegistry registry){
        registry.addViewController("/ws").setViewName("/ws");
    }
  	//將所有/static/** 存取都對映到classpath:/static/ 目錄下
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        System.out.println("==========靜態資源攔截!============");
        registry.addResourceHandler("/static/**/").addResourceLocations("classpath:/static/");
    }
}

跑跑跑起來…
運行結果
ps:以上內容參考SpringBoot顛覆者,學習筆記,僅供參考