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HTML5 Web socket和socket.io

2014-05-19 17:35 555 查看

what is websockets


Two-way communication over ont TCP socket, a type of PUSH technology


  HTML5的新特性,用于双向推送消息(例如网页聊天,手机推送消息等)

  原理:

client利用regular http请求webpage

请求的webpage 执行javascript脚本,open a connection to server.

有新的信息时服务器和客户端可以相互发送信息(Real-time traffic from the server to the client and from the client to the server

  


客户端

  说明:

  readyState:


CONNECTING (0):表示还没建立连接;
OPEN (1): 已经建立连接,可以进行通讯;
CLOSING (2):通过关闭握手,正在关闭连接;
CLOSED (3):连接已经关闭或无法打开;


  

  url: WebSocket 服务器的网络地址,协议通常是”ws”或“wss(加密通信)”,

  事件:



send:向服务器端发送数据

close 方法就是关闭连接;

onopen连接建立,即握手成功触发的事件;

onmessage收到服务器消息时触发的事件;

onerror异常触发的事件;


 

  使用例子:

// 创建一个Socket实例
var socket = new WebSocket('ws://localhost:8080');

// 打开Socket
socket.onopen = function(event) {

// 发送一个初始化消息
socket.send('I am the client and I\'m listening!');

// 监听消息
socket.onmessage = function(event) {
console.log('Client received a message',event);
};

// 监听Socket的关闭
socket.onclose = function(event) {
console.log('Client notified socket has closed',event);
};

// 关闭Socket....
//socket.close()
};


服务器端

 jWebSocket (Java)
 web-socket-ruby (ruby)
 Socket IO-node (node.js)

 下面以socket.io说明,环境说明:(node.js安装见 /article/6198127.html

 1. 安装socket.io


 npm install -g socket.io


2.使用require引入http和socket.io

var http = require("http");
var io= require('socket.io');


3.创建server

var server = http.createServer(function(request, response){
response.writeHead(200,{"Content-Type":"text/html"});
response.write("WebSocket Start~~~~~~~~~~~~");
response.end("");
}).listen(8000);


4.监听

var socket= io.listen(server);


5.例子:

var http = require("http");
var io= require('socket.io');
var server = http.createServer(function(request, response){ response.writeHead(200,{"Content-Type":"text/html"}); response.write("WebSocket Start~~~~~~~~~~~~"); response.end(""); }).listen(8000);

var socket= io.listen(server);

// 添加一个连接监听器
socket.on('connection', function(client){

client.on('message',function(event){
console.log('Received message from client!',event);
});
client.on('disconnect',function(){
clearInterval(interval);
console.log('Server has disconnected');
});
});


数据发送两种方式send和emit

使用send和emit都可以发送数据,但是emit可以自定义事件,如下:

emit:

//服务器

socket.on('connection', function(client){
client.on('message',function(event){
client.emit('emitMessage', { hello: 'messgge received, wish you happy'+new Date().toString() });
});

});

//客户端
socket.on('emitMessage',function(data) {
document.getElementById("result").innerHTML+=data.hello + "<br />";

});


send:

//服务器

socket.on('connection', function(client){
client.send('hello, I am the server');
});

//客户端
socket.on('message',function(data) {
document.getElementById("result").innerHTML+=data + "<br />";

});


实例:(socket.io)

客户端:

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<style>
div{
border-radius: 10px;
border: 2px solid pink;
width:800px;
}
</style>
</head>
<body>
<h1></h1>
<div id="result"></div>
<script src="http://localhost:8000/socket.io/socket.io.js"></script>
<script>
//创建Socket.IO实例,建立连接

var socket = io.connect('http://localhost:8000');

// 添加一个连接监听器
socket.on('connect',function() {
console.log('Client has connected to the server!');
});

// 添加一个连接监听器
socket.on('message',function(data) {
document.getElementById("result").innerHTML+=data + "<br />";

});
socket.on('emitMessage',function(data) {
document.getElementById("result").innerHTML+=data.hello + "<br />";

});

// 添加一个关闭连接的监听器
socket.on('disconnect',function() {
console.log('The client has disconnected!');
});

// 通过Socket发送一条消息到服务器
function sendMessageToServer(message) {
socket.send(message);
}
var date = new Date();
var ms="Time: "+date.toString()+"Today is a nice day, wish you happy";
setInterval("sendMessageToServer(ms)",1000);
</script>

</body>
</html>


服务器:

var http = require("http");
var io= require('socket.io');
var server = http.createServer(function(request, response){ response.writeHead(200,{"Content-Type":"text/html"}); response.write("WebSocket Start~~~~~~~~~~~~"); response.end(""); }).listen(8000);

var socket= io.listen(server);

// 添加一个连接监听器
socket.on('connection', function(client){

client.on('message',function(event){
console.log('Received message from client!',event);
client.emit('emitMessage', { hello: 'messgge received, wish you happy'+new Date().toString() });
});
client.on('disconnect',function(){
// clearInterval(interval);
console.log('Server has disconnected');
});
client.send('hello, I am the server');
});


结果:

客户端:



服务器端:



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