政府网站建设任务网络营销app有哪些
websocket轮询每隔5秒给服务端send一次信息,主要功能点如下:
socket 采用了定时器 setInterval() 需要清除定时器否则会报错
监听了突然关闭浏览器窗口,destroyed里面直接监听 window.removeEventListener("beforeunload", e => this.beforeunloadHandler(e)) 然后调用this.webstock.close()关闭socket的长链接。
WebSocket连接发生错误的时候,连接错误 需要重连this.reConnect(),尝试重新连接,本次重连次数大于6次就不连接了,放弃连接。
先上效果图:


一 、功能点一清除定时器:
clearInterval(this.timer) // 清除定时器
二、功能点二监听了突然关闭浏览器窗口:
mounted() {window.addEventListener("beforeunload", e => this.beforeunloadHandler(e))window.addEventListener("unload", e => this.unloadHandler(e))},
beforeunloadHandler() {this._beforeUnload_time = new Date().getTime();},unloadHandler(e) {this._gap_time = new Date().getTime() - this._beforeUnload_time;// debugger// 关闭或刷新窗口都保存数据到后台// 判断窗口是关闭还是刷新if (this._gap_time <= 5) {// 关闭连接this.webstock.close()} }
destroyed() {this.$destroy()clearInterval(this.timer) // 清除定时器// 页面销毁时关闭长连接// if (this.webstock !== null) {// this.webstock.close()// } window.removeEventListener("beforeunload", e => this.beforeunloadHandler(e))window.removeEventListener("unload", e => this.unloadHandler(e))}
三、功能点三WebSocket连接发生错误的时候,连接错误 需要重连
websocketonerror(e) {console.log("WebSocket连接发生错误")// 连接断开后修改标识this.isConnect = false// 连接错误 需要重连this.reConnect()}},
全部代码如下:
<template>
</template><script>
export default {data() {return {timer: 5000,webstock: '', // webSocket使用isConnect: false, // webSocket连接标识 避免重复连接reConnectNum: 1, // 断开后重新连接的次数 免得后台挂了,前端一直重连_beforeUnload_time: null,_gap_time: null}},methods: {/*webSocket start*/initWebSocket() {let userId = this.$store.state.user.userIdif (userId !== null && userId !== '') {// WebSocket与普通的请求所用协议有所不同,ws等同于http,wss等同于https// 本地环境// let wsServer =// `${// location.protocol === "https" ? "wss" : "ws"// }://localhost:9106/接口前缀/websocket/` + userId;// 线上环境let wsServer = 'ws://172.16.0.54:8102/api/webSocket/' + userIdconsole.log("wsServer:", wsServer)this.webstock = new WebSocket(wsServer)this.webstock.onopen = this.websocketonopenthis.webstock.onerror = this.websocketonerrorthis.webstock.onmessage = this.websocketonmessagethis.webstock.onclose = this.websocketclose}},websocketonopen() {console.log("WebSocket连接成功") // 连接建立后修改标识this.isConnect = trueconst timeoutInfoId = '420507657544310784'clearInterval(this.timer) // 清除定时器const that = thissetInterval(() => {if (window.location.pathname === '/standardTemplate') {that.webstock.send(timeoutInfoId)}}, this.timer)},websocketonerror(e) {console.log("WebSocket连接发生错误")// 连接断开后修改标识this.isConnect = false// 连接错误 需要重连// this.reConnect()if (window.location.pathname === '/standardTemplate') {this.reConnect()}},// 接收后端推送过来的消息websocketonmessage(e) {console.log("message消息:", e.data)// if (e != null) {// let str = JSON.parse(e.data)// }},websocketclose(e) {console.log("webSocket连接关闭")// 连接断开后修改标识this.isConnect = falsethis.webstock = ''if (window.location.pathname === '/standardTemplate') {this.reConnect()}},// 重新连接reConnect() {console.log("尝试重新连接,本次重连次数:" + this.reConnectNum)if (this.reConnectNum > 6) {return false}// 如果已经连上就不再重试了if (this.isConnect) returnthis.initWebSocket()this.reConnectNum = this.reConnectNum + 1},/*webSocket end*/beforeunloadHandler() {this._beforeUnload_time = new Date().getTime();},unloadHandler(e) {this._gap_time = new Date().getTime() - this._beforeUnload_time;// debugger// 关闭或刷新窗口都保存数据到后台// 判断窗口是关闭还是刷新if (this._gap_time <= 5) {// 关闭连接this.webstock.close()} }},created() {this.reConnectNum = 1this.initWebSocket()},mounted() {window.addEventListener("beforeunload", e => this.beforeunloadHandler(e))window.addEventListener("unload", e => this.unloadHandler(e))},destroyed() {this.$destroy()clearInterval(this.timer) // 清除定时器// 页面销毁时关闭长连接// if (this.webstock !== null) {// this.webstock.close()// } window.removeEventListener("beforeunload", e => this.beforeunloadHandler(e))window.removeEventListener("unload", e => this.unloadHandler(e))}
}
</script>
问题一、
报错信息如下:socketReport.vue?8285:51 Uncaught DOMException: Failed to execute 'send' on 'WebSocket': Still in CONNECTING state.

要明白这个问题产生的原因,就需要了解websocket的几个状态。通常在实例化一个websocket对象之后,客户端就会与服务器进行连接。但是连接的状态是不确定的,于是用readyState属性来进行标识。它有四个值,分别对应不同的状态:
CONNECTING:值为0,表示正在连接;
OPEN:值为1,表示连接成功,可以通信了;
CLOSING:值为2,表示连接正在关闭;
CLOSED:值为3,表示连接已经关闭,或者打开连接失败。
这样问题的原因就很明显了,之所以数据不能发送出去,是因为websocket还处在“CONNECTING”状态下,连接还没有成功。
解决办法
只要在函数中添加对状态的判断,在状态为OPEN时,执行send方法即可。方法一代码如下
this.init()
if (this.webstock.readyState===1) {this.webstock.send()
}
问题二、vue项目中监听电脑网络的状态,突然断开网络或者关机
写法一、
data() {return {network: true, //默认有网}
}
mounted() {window.addEventListener("online", () => {console.log("网络已连接:")this.network = true})// 检测断网window.addEventListener("offline", () => {console.log("已断网:")this.network = falseif (this.webstock !== null) {this.webstock.close()} })
}
控制台打印的结果:
断开网络的情况

再次连接网络:

写法二、
data() {return {onLine: navigator.onLine,}
}
mounted() {console.log('this.onLine:', this.onLine)window.addEventListener('beforeunload', e => this.beforeunloadHandler(e))window.addEventListener('unload', e => this.unloadHandler(e))}
beforeDestroy(){window.removeEventListener('online', this.updateOnlineStatus);window.removeEventListener('offline', this.updateOnlineStatus);},
// 检测断网updateOnlineStatus(e) {const { type } = e// this.onLine = type === 'online'if (type === 'online') {// 网络已连接console.log("网络已连接:")this.$emit('fatherMethod')if (window.location.pathname === '/newReport' || window.location.pathname === '/c3analysis') {if (!this.unLock){this.reConnect()}}} else if (type === 'offline') {// 已断网console.log("已断网:")if (this.webstock !== null) {this.webstock.close()} }},
