• websocket实现心跳连接


    在使用websocket的时候,遇到了一个websocket在连接一段时间就异常断开连接了。第一想法就是重新去连接websocket(websock.onopen),后来发现这种方式是错误的,查阅文档发现,要想重新建立连接,就需要一种心跳思想去处理(实时监听连接情况,断了就去重连)
    下面以Vue代码为准:


    let lockReconnect = false;//避免重复连接
    let wsUrl = '‘ // url;
    let ws;
    let tt;


    createWebSocket() {
    let that = this;
    try {
    ws = new WebSocket(wsUrl);
    this.init();
    } catch(e) {
    console.log('catch');
    that.reconnect(wsUrl);
    }
    },
    init() {
    let that = this;

    //心跳检测
    let heartCheck = {
    timeout: 3000,
    timeoutObj: null,
    serverTimeoutObj: null,
    start: function(){
    console.log('start');
    let self = this;
    this.timeoutObj && clearTimeout(this.timeoutObj);
    this.serverTimeoutObj && clearTimeout(this.serverTimeoutObj);
    this.timeoutObj = setTimeout(function(){
    //这里发送一个心跳,后端收到后,返回一个心跳消息,
    console.log('55555');
    ws.send("888");
    self.serverTimeoutObj = setTimeout(function() {
    console.log(111);
    console.log(ws);
    ws.close();
    // createWebSocket();
    }, self.timeout);

    }, this.timeout)
    }
    };
    ws.onclose = function () {
    console.log('链接关闭');
    that.reconnect(wsUrl);
    location.reload()
    };
    ws.onerror = function() {
    console.log('发生异常了');
    that.reconnect(wsUrl);
    location.reload();
    };
    ws.onopen = function () {
    //心跳检测重置
    heartCheck.start();
    };
    ws.onmessage = function (e) {
    //拿到任何消息都说明当前连接是正常的
    console.log('接收到消息');
    console.log(e);

    heartCheck.start();
    }
    },
    reconnect(url) {
    if(lockReconnect) {
    return;
    }
    lockReconnect = true;
    //没连接上会一直重连,设置延迟避免请求过多
    tt && clearTimeout(tt);
    tt = setTimeout( () => {
    this.createWebSocket(url);
    lockReconnect = false;
    }, 4000);
    },

    this.createWebSocket(wsUrl);

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  • 原文地址:https://www.cnblogs.com/exmyth/p/11588696.html
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