H5 Server Sent Event服务端主动发送数据回客户端代码实例
导读：收集整理的这篇文章主要介绍了html5教程-H5 Server Sent Event服务端主动发送数据回客户端代码实例，觉得挺不错的，现在分享给大家，也给大家做个参考。小宝典致力于为广大程序猿（媛）提供高品质的代码服务，请大家多多光顾小站，...
收集整理的这篇文章主要介绍了html5教程-H5 Server Sent Event服务端主动发送数据回客户端代码实例，觉得挺不错的，现在分享给大家，也给大家做个参考。小宝典致力于为广大程序猿（媛）提供高品质的代码服务，请大家多多光顾小站，小宝典在此谢过。 效果图
Server Sent Event
Server Sent Event通过EventSource对象接收服务器发送事件的通知. 有三个事件message, oPEn, error
下面的代码演示了使用的方法
例子代码运行环境: node.js
代码
粘贴下面代码运行node index.js
//index.htML !DOCTYPE html>
html lang="en">
head>
meta charset="UTF-8">
meta name="viewport" content="width=device-width, inITial-scale=1.0">
meta http-equiv="X-UA-Compatible" content="ie=Edge">
title>
Server-sent/title>
/head>
body>
script>
window.addEventListener("load",function () {
let status = document.getElementById("status");
let output = document.getElementById("output");
let source;
function connect() {
source = new EventSource("stream");
//与服务器端建立连接 //鉴定message事件, 获取服务端发送的数据 source.addEventListener("message", function (event) {
output.textContent = event.data;
}
, false);
//监听open事件, 判断连接是否进行中 source,addEventListener("open", function (event) {
status.textContent = '连接打开了';
}
,false);
//监听error事件, 处理连接错误的情况 source.addEventListener("error", function (event) {
if (event.target.readyState === EventSource.CLOSED) {
source.close();
status.textContent = '连接关闭了';
}
else {
status.textContent = "连接关闭了!未知错误!";
}
}
, false);
}
if(!!window.EventSource) {
connect();
}
else {
status.textContent = "不支持server-sent" }
}
,false);
/script>
span id="status">
Connection closed!/span>
br>
span id="output">
/span>
/body>
/html>
服务端代码
//index.js const http = require('http');
const fs = require('fs');
http.createServer(function (req, res) {
let interval, fileName, index = "./index.html";
console.LOG(req.url);
if(req.url === "/") {
fileName = index;
}
else {
fileName = "." + req.url;
}
if (fileName === "./stream") {
//如果server sent event则设置相应头信息 res.writeHead(200, {
"Content-type" : "text/event-stream", "Cache-Control" : "no-cache", "Connection": "keep-alive", }
) res.write("retry: 10000/n");
//过10000秒重试 res.write("data: " + (new Date()) + "/n/n");
interval = setInterval(function () {
res.write("data: " + (new Date()) + "/n/n");
}
, 1000);
//监听close事件, 用于停止定时器 req.connection.addListener("close", function () {
clearInterval(interval);
}
, false);
}
else if (fileName === index) {
//判断是否为页面请求, 并找到相应文件返回页面 fs.exists(fileName, function (exists) {
if (exists) {
fs.reaDFile(fileName, function (error, content) {
if (error) {
res.writeHead(500);
res.end();
}
else {
res.writeHead(200, {
"Content-Type" : "text/html"}
);
res.end(content, "utf-8");
}
}
) }
else {
console.log(123);
res.writeHead(404);
res.end();
}
}
) }
else {
res.writeHead(404);
res.end();
}
}
).listen(8080, "127.0.0.1");
console.log("at 8080");
效果图
Server Sent Event
Server Sent Event通过EventSource对象接收服务器发送事件的通知. 有三个事件message, open, error
下面的代码演示了使用的方法
例子代码运行环境: node.js
代码
粘贴下面代码运行node index.js
//index.html !DOCTYPE html>
html lang="en">
head>
meta charset="UTF-8">
meta name="viewport" content="width=device-width, initial-scale=1.0">
meta http-equiv="X-UA-Compatible" content="ie=edge">
title>
server-sent/title>
/head>
body>
script>
window.addEventListener("load",function () {
let status = document.getElementById("status");
let output = document.getElementById("output");
let source;
function connect() {
source = new EventSource("stream");
//与服务器端建立连接 //鉴定message事件, 获取服务端发送的数据 source.addEventListener("message", function (event) {
output.textContent = event.data;
}
, false);
//监听open事件, 判断连接是否进行中 source,addEventListener("open", function (event) {
status.textContent = '连接打开了';
}
,false);
//监听error事件, 处理连接错误的情况 source.addEventListener("error", function (event) {
if (event.target.readyState === EventSource.CLOSED) {
source.close();
status.textContent = '连接关闭了';
}
else {
status.textContent = "连接关闭了!未知错误!";
}
}
, false);
}
if(!!window.EventSource) {
connect();
}
else {
status.textContent = "不支持server-sent" }
}
,false);
/script>
span id="status">
Connection closed!/span>
br>
span id="output">
/span>
/body>
/html>
服务端代码
//index.js const http = require('http');
const fs = require('fs');
http.createServer(function (req, res) {
let interval, fileName, index = "./index.html";
console.log(req.url);
if(req.url === "/") {
fileName = index;
}
else {
fileName = "." + req.url;
}
if (fileName === "./stream") {
//如果server sent event则设置相应头信息 res.writeHead(200, {
"Content-Type" : "text/event-stream", "Cache-Control" : "no-cache", "Connection": "keep-alive", }
) res.write("retry: 10000/n");
//过10000秒重试 res.write("data: " + (new Date()) + "/n/n");
interval = setInterval(function () {
res.write("data: " + (new Date()) + "/n/n");
}
, 1000);
//监听close事件, 用于停止定时器 req.connection.addListener("close", function () {
clearInterval(interval);
}
, false);
}
else if (fileName === index) {
//判断是否为页面请求, 并找到相应文件返回页面 fs.exists(fileName, function (exists) {
if (exists) {
fs.readFile(fileName, function (error, content) {
if (error) {
res.writeHead(500);
res.end();
}
else {
res.writeHead(200, {
"Content-Type" : "text/html"}
);
res.end(content, "utf-8");
}
}
) }
else {
console.log(123);
res.writeHead(404);
res.end();
}
}
) }
else {
res.writeHead(404);
res.end();
}
}
).listen(8080, "127.0.0.1");
console.log("at 8080");
觉得可用，就经常来吧！ 欢迎评论哦！ html5教程，巧夺天工，精雕玉琢。小宝典献丑了！
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