websocket学习

<template>
    <!-- {{flag}} -->
    <div id="myChart" :style="{ width: '300px', height: '300px' }"></div>
</template>
<script setup>
// 导入echarts
import * as echarts from 'echarts'
// 配置项
const option = reactive({
    xAxis: {
        type: 'category',
        data: ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
    },
    yAxis: {
        type: 'value'
    },
    series: [{
        data: [150, 230, 224, 218, 135, 147, 260],
        type: 'line'
    }]
});
const initeCharts = () => {
    let myChart = echarts.init(document.getElementById('myChart'))
    // 绘制图表
    myChart.setOption(option)
}
// 生命周期函数
onMounted(() => {
    initeCharts()
})

// websocket 实现数据的实时更新
// 1. 新建对象
const ws = new WebSocket("ws://127.0.0.1:3000")
// console.log(ws)
// 2. 开始连接
ws.onopen = function() {
    alert('WebSocket连接成功')
}
ws.onerrow = function() {
    alert('WebSocket连接失败')
}
// 获取到的数据  这里会不断的接收后端返回的数据
ws.onmessage = function(data) {
    alert(data)
}
</script>
<style scoped>
.logo {
    height: 6em;
    padding: 1.5em;
    will-change: filter;
    transition: filter 300ms;
}

.logo:hover {
    filter: drop-shadow(0 0 2em #646cffaa);
}

.logo.vue:hover {
    filter: drop-shadow(0 0 2em #42b883aa);
}
</style>

后端 nodejs 

var ws = require("nodejs-websocket")

var PORT = 3000

var server = ws.createServer(function(conn) {

    console.log("New connection")
    conn.on("text", function(str) {
        console.log("Received " + str)
        conn.sendText(str.toUpperCase() + "!!!")
    })
    conn.on("close", function(code, reason) {
        console.log("Connection closed")
    })

    conn.on("error", function(err) {
        console.log("handle err");
        console.log(err);
        console.log(err);
    })

}).listen(PORT)