java 广播方法 spring 广播

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误会一场 2023-11-11 21:33:34

文章标签 java 广播方法 Spring SpringMVC websocket 广播通信 文章分类 Java 后端开发

前言

&nsbp; 最近在搞一个websocket的小尝试，打算用在前后端分离的项目上，先拿后端做个尝试，特此记录下。

正文

一、引入maven 依赖

<dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-websocket</artifactId>
      <version>${spring.version}</version>
</dependency>
 <dependency>
     <groupId>org.springframework</groupId>
     <artifactId>spring-messaging</artifactId>
     <version>${spring.version}</version>
 </dependency>

二、准备常量类

package com.dmsdbj.itoo.utils;

public class Constant {

    //webSocket相关配置
    //链接地址
    public static String WEBSOCKETPATHPERFIX = "/ws-push";
    public static String WEBSOCKETPATH = "/endpointWisely";
    //消息代理路径
    public static String WEBSOCKETBROADCASTPATH = "/topic";
    //前端发送给服务端请求地址
    public static final String FORETOSERVERPATH = "/welcome";
    //服务端生产地址,客户端订阅此地址以接收服务端生产的消息
    public static final String PRODUCERPATH = "/topic/getResponse";
    //点对点消息推送地址前缀
    public static final String P2PPUSHBASEPATH = "/user";
    //点对点消息推送地址后缀,最后的地址为/user/用户识别码/msg
    public static final String P2PPUSHPATH = "/msg";
}

三、定义两个消息实体

//接收前端消息实体
public class WiselyMessage {
    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}
//后台发送消息实体
private String responseMessage;

    public WiselyResponse(String responseMessage){
        this.responseMessage = responseMessage;
    }

    public String getResponseMessage() {
        return responseMessage;
    }

    public void setResponseMessage(String responseMessage) {
        this.responseMessage = responseMessage;
    }

四、配置websocket

@Configuration
// 开始支持@MessageMapping,就像是使用@requestMapping一样。
@EnableWebSocketMessageBroker
public class WebSocketConfig  implements WebSocketMessageBrokerConfigurer {

    @Override
    public void registerStompEndpoints(StompEndpointRegistry stompEndpointRegistry) {
        //注册一个Stomp的节点（endpoint）,并指定使用SockJS协议
        stompEndpointRegistry.addEndpoint(Constant.WEBSOCKETPATH). setAllowedOrigins("*").withSockJS();
    }


    // 配置消息
    @Override
    public void configureMessageBroker(MessageBrokerRegistry registry) {
        //服务端发送消息给客户端的域,多个用逗号隔开
        registry.enableSimpleBroker(Constant.WEBSOCKETBROADCASTPATH, Constant.P2PPUSHBASEPATH);
        //定义一对一推送的时候前缀
        registry.setUserDestinationPrefix(Constant.P2PPUSHBASEPATH);
        //定义websoket前缀---服务端地址前缀
        registry.setApplicationDestinationPrefixes(Constant.WEBSOCKETPATHPERFIX);
    }
}

五、控制器类

@RequestMapping("/onlineExam")
@Controller
public class OnlineExamController {

    @Autowired
    private OnlineExamFacade onlineExamFacade;
    // 配置访问subws.html
    @RequestMapping(value={"subws"},method=RequestMethod.GET)
    public String subws(){
        return"subws";
    }
    // 配置访问sendws.html
    @RequestMapping(value={"sendws"},method=RequestMethod.GET)
    public String sendws(){
        return"sendws";
    }
    //订阅消息测试--添加用户信息
    @GetMapping("/insert")
    @ResponseBody
    public boolean insertUser(String userId){
        return onlineExamFacade.insertUser(userId);
    }

    @Autowired
    private SimpMessagingTemplate template;

    //广播发送消息
    @MessageMapping(Constant.FORETOSERVERPATH)//@MessageMapping和@RequestMapping功能类似，用于设置URL映射地址，浏览器向服务器发起请求，需要通过该地址。
    public WiselyResponse say(WiselyMessage message) throws Exception {
    // 所有用户
        List<String> userId = onlineExamFacade.send2Users();
        userId.forEach(s->{
            template.convertAndSendToUser(s.toString(), Constant.P2PPUSHPATH, new WiselyResponse(message.getName()));
        });
        return null;
    }

六、HTML 页面（部分代码）

//***************subws.html*******************
<!DOCTYPE html>
<div>
    <div>
        <button id="connect" onclick="connect();">连接</button>
        <button id="disconnect" disabled="disabled" onclick="disconnect();">断开连接</button>
    </div>
    <div id="conversationDiv">
        <label>输入你的userId</label><input type="text" id="userId" />
        <button id="subMsg" onclick="subMsg();">订阅消息</button>
        <p id="response"></p>
        <p id="response1"></p>
    </div>
</div>
<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;
    //此值有服务端传递给前端,实现方式没有要求
    //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() {
         // 注意 SockJS()中传入的地址  一定要正确
        var socket = new SockJS('/exam-web/endpointWisely');
        stompClient = Stomp.over(socket);//2创建STOMP协议的webSocket客户端。
        stompClient.connect({}, function(frame) {//3连接webSocket的服务端。
            setConnected(true);
            console.log('开始进行连接Connected: ' + frame);
        });
    }

    //订阅消息
    function subMsg() {
        var userId = $('#userId').val();
        console.log(userId);
        $.ajax({
            type: 'GET',
            url: '/exam-web/onlineExam/insert?userId='+userId,
            success: function (data) {
                console.log(data);
                //4通过stompClient.subscribe（）订阅服务器的目标是'/user/' + userId + '/msg'接收一对一的推送消息,其中userId由服务端传递过来,用于表示唯一的用户,通过此值将消息精确推送给一个用户
                stompClient.subscribe('/user/' + userId + '/msg', function(respnose){
                    console.log(respnose);                   showResponse1(JSON.parse(respnose.body).responseMessage);
                });
            }
        });
    }
</script>
</body>
</html>

<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;
    //此值有服务端传递给前端,实现方式没有要求
    //var userId = [[${userId}]];
    var userId = 'd892bf12bf7d11e793b69c5c8e6f60fb';
     ……
    // 建立连接方法
    function connect() {
        var socket = new SockJS('/exam-web/endpointWisely');
        stompClient = Stomp.over(socket);//2创建STOMP协议的webSocket客户端。
        stompClient.connect({}, function(frame) {//3连接webSocket的服务端。
            setConnected(true);
            console.log('开始进行连接Connected: ' + frame);
        });
    }


    function disconnect() {
        if (stompClient != null) {
            stompClient.disconnect();
        }
        setConnected(false);
        console.log("Disconnected");
    }

//    输入名字之后，点击发送消息
    function sendName() {
        var name = $('#name').val();
        console.log(name);
        //通过stompClient.send（）向地址为"/welcome"的服务器地址发起请求，与@MessageMapping里的地址对应。因为我们配置了registry.setApplicationDestinationPrefixes(Constant.WEBSOCKETPATHPERFIX);所以需要增加前缀/ws-push/
        stompClient.send("/ws-push/welcome", {}, JSON.stringify({ 'name': name }));
    }

七、效果展示

接收端：先连接，连接成功后，‘订阅’消息成功后，收到了发送端的‘你好’消息

java 广播方法 spring 广播_SpringMVC

发送端：发送了‘你好’消息

java 广播方法 spring 广播_SpringMVC_02

八、遇到的问题：lost connection to http://localhost:8089/endpointWisely

java 广播方法 spring 广播_websocket_03

解决：

function connect() {
         //*********错误的写法************/
        //var socket = new SockJS('/endpointWisely'); //1连接SockJS的endpoint是“endpointWisely”，与后台代码中注册的endpoint要一样。
        //*********正确的写法************/
        var socket = new SockJS('/exam-web/endpointWisely');

        stompClient = Stomp.over(socket);//2创建STOMP协议的webSocket客户端。