HTML5 Web Sockets

相关资料

具体介绍：http://www.html5rocks.com/zh/tutorials/websockets/basics/

浏览器支持版本：http://stackoverflow.com/questions/1253683/what-browsers-support-html5-websocket-api

什么是 WebSockets

WebSockets是HTML5提供的一个支持客户端和服务器之间进行实时通讯数据推送的非HTTP通信机制。使用Web Sockets 可以在服务器和客户端之间建立一个非HTTP的双向连接。Web Sockets在不被关闭的条件下，这个连接是实时的、永久的。这样的机制实现了服务器不再需要轮询客户端的请求，从被动转为了主动。

WebSockets并非HTTP但他也带有HTTP的开销，所以在使用Web Sockets的时候并不适用于低延迟应用。

WebSockets的使用

1.创建websockets对象（将url作为参数交给websockets）

varwebSocket = new WebSocket(“ws://localhost:8005/socket”);

请注意 ws:。这是 WebSocket连接的新网址架构。对于安全 WebSocket 连接还有wss:，就像 https: 用于安全 HTTP 连接一样。

2.与服务器通信

webSockets.send(data);//发送数据

webSockets.onmessage= function(ev){ var data = ev.data;}//接收数据

在通信过程中webSockets主要包含了四个状态：

1.CONNECTING(数字值为0)，表示正在连接

2.OPEN(数字值为1)，表示已经建立好连接

3.CLOSING(数字值为2)，表示正在关闭连接

4.CLOSED(数字值为2)，表示已经关闭连接

webSockets无论发送还是接收都只支持字符串类型，在需要传输JSON对象的时候，可以通过JSON的stringify方法和parse进行转换。

在最新规范中，WebSocket 也可以接收二进制讯息。接收的二进制帧可以是 Blob或 ArrayBuffer 格式。要指定收到的二进制数据的格式，可将WebSocket 对象的 binaryType 属性设为“blob”或“arraybuffer”。默认格式为“blob”（您不必在发送时校正 binaryType 参数）WebSocket 的另一个新增功能是扩展。利用扩展，可以发送压缩帧、多路复用帧等。您可以检查 open 事件后的 WebSocket 对象的 extensions 属性，查找服务器所接受的扩展。截止 2012 年 2 月，还没有官方发布的扩展规范。

WebSockets的服务器支持

lNode.js

uSocket.IO

uWebSocket-Node

uws

lJava

uJetty

lRuby

uEventMachine

lPython

upywebsocket

uTornado

lErlang

uShirasu

lC++

ulibwebsockets

l.NET

uSuperWebSocket

客服端服务器详细支持情况

Client side

·Hixie-75:

·Chrome 4.0 + 5.0

·Safari 5.0.0

·HyBi-00/Hixie-76:

·Chrome 6.0 - 13.0

·Safari 5.0.2 + 5.1

·iOS 4.2 + iOS 5

·Firefox 4.0 -support for WebSocketsdisabled. To enable itsee here.

·Opera 11 -with support disabled. To enable itsee here.

·HyBi-07+:

·Chrome 14.0

·Firefox 6.0 - prefixed:MozWebSocket

·IE 9 - viadownloadable Silverlightextension

·HyBi-10:

·Chrome 14.0 + 15.0

·Firefox 7.0 + 8.0 + 9.0 + 10.0 -prefixed:MozWebSocket

·IE 10 (from Windows 8 developerpreview)

·HyBi-17/RFC 6455

·Chrome 16

·Firefox 11

·Opera 12.10 / Opera Mobile 12.1

Any browser with Flash can support WebSocket using theweb-socket-jsshim/polyfill.

Seecaniusefor the current status of WebSocketssupport in desktop and mobile browsers.

See thetest reportsfrom the WS testsuite included inAutobahn WebSocketsfor feature/protocol conformancetests.

Server side

InJava/Java EE:

·Jetty 7.0supports it (very easy to use)V 7.5 supports RFC6455-Jetty 9.1supports javax.websocket / JSR 356)

·GlassFish 3.0(very low level and sometimescomplex), Glassfish 3.1 has new refactored Websocket Support which is moredeveloper friendlyV 3.1.2 supports RFC6455

·Caucho Resin 4.0.2(not yet tried)V 4.0.25 supports RFC6455

·Tomcat 7.0.27now supports itV 7.0.28 supports RFC6455

·JSR356 included in Java EE 7willdefine the Java API for WebSocket,but is not yet stable andcomplete. See Arun GUPTA‘s articleWebSocket and Java EE 7 -Getting Ready for JSR 356 (TOTD #181)andQCon presentation(from 00:37:36 to 00:46:53) for moreinformation on progress. You can also look atJavawebsocket SDK.

Someother Java implementations:

·Kaazing Gateway

·jWebscoket

·Netty

·xLightWeb

·Webbit

·Atmosphere

·Grizzly

·ApacheActiveMQV 5.6 supports RFC6455

·Apache CamelV 2.10 supports RFC6455

·JBossHornetQ

In C#:

·XSockets.NET

·SuperWebSocket

·Nugget

·Alchemy-Websockets

·Fleck

·SignalR

In PHP:

·Ratchet

·phpwebsocket.

·Extendible Web Socket Server

·phpdaemon

InPython:

·pywebsockets

·websockify

·gevent-websocket,gevent-socketioandflask-socketsbasedon the former

·Autobahn

·Tornado

In C:

·libwebsockets

InNode.js:

·Socket.io: Socket.io also has serverside portsfor Python, Java, Google GO, Rack

·sockjs: sockjs also has serverside ports forPython, Java, Erlang and Lua

·WebSocket-Node-Pure JavaScript Client & Server implementation of HyBi-10.

Vert.x (also known as Node.x): A node like polyglot implementationrunning on a Java 7 JVM and based on Netty with :

·Support for Ruby(JRuby), Java,Grovy, Javascript(Rhino/Nashorn), Scala, ...

·True threading. (unlike Node.js)

·Understands multiple networkprotocols out of the box including: TCP, SSL, UDP, HTTP, HTTPS, Websockets,SockJSasfallback for WebSockets

Pusher.comis a Websocket cloud serviceaccessible through a REST API.

DotCloudcloudplatform supports Websockets, and Java (Jetty Servlet Container), NodeJS,Python, Ruby, PHP and Perl programming languages.

Openshiftcloudplatform supports websockets, and Java (Jboss, Spring, Tomcat & Vertx), PHP(ZendServer & CodeIgniter), Ruby (ROR), Node.js, Python (Django &Flask) plateforms.

For other language implementations,see the Wikipedia article for more information.

The RFC for Websockets :RFC6455

本文出自 “插上javaScript的翅膀” 博客，请务必保留此出处http://shimengwen.blog.51cto.com/2448562/1361421