WebSocket学习
客户端连接
客户端
<script> var socket = new WebSocket("ws://127.0.0.1:8000/chat"); </script>
服务端
import socket sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) sock.bind(('127.0.0.1', 8000)) sock.listen(5) conn, address = sock.accept() print('有链接过来。。。') data = conn.recv(1024) print(data) """ GET /chat HTTP/1.1\r\n Host: 127.0.0.1:8000\r\n Connection: Upgrade\r\n Pragma: no-cache\r\n Cache-Control: no-cache\r\n Upgrade: websocket\r\n Origin: http://localhost:63342\r\n Sec-WebSocket-Version: 13\r\n User-Agent: Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.186 Safari/537.36\r\n Accept-Encoding: gzip, deflate, br\r\n Accept-Language: zh-CN,zh;q=0.9\r\n Sec-WebSocket-Key: CyiOUMgm4Qd6WyjLQ+YbrA==\r\n Sec-WebSocket-Extensions: permessage-deflate; client_max_window_bits\r\n\r\n """ conn.send("响应【握手】信息".encode('utf-8')) conn.close()
浏览器发起了连接请求,其中包含了握手信息,服务端要想握手成功达成连接,需要满足下面几个条件:
- 首先获取客户端发来的 Sec-WebSocket-Key ,然后把这个值和 magic_string(258EAFA5-E914-47DA-95CA-C5AB0DC85B11)连接起来。
- 然后进行 SHA-1 hash 加密,最后再进行 base64 加密。
- 最后得到的值赋值给 Sec-WebSocket-Accept 字段当做响应头发给客户端。
响应头格式如下:
HTTP/1.1 101 Switching Protocols Upgrade: websocket Connection: Upgrade Sec-WebSocket-Accept: s3pPLMBiTxaQ9kYGzzhZRbK+xOo=
建立连接(握手)
客户端
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <button onclick="connection_check()">check</button> <script> var socket = new WebSocket("ws://127.0.0.1:8000/chat"); function connection_check() { if(0 == socket.readyState) { alert('尚未建立连接'); } else if(1 == socket.readyState) { alert('连接已建立'); } else if(2 == socket.readyState) { alert('连接正在进行关闭'); } else { alert('连接已经关闭或者连接不能打开'); } } </script> </body> </html>
服务端
import socket import hashlib import base64 def get_headers(data): """ 将请求头格式化成字典 :param data: :return: """ header_dict = {} data = str(data, encoding='utf-8') header, body = data.split('\r\n\r\n', 1) header_list = header.split('\r\n') for i in range(0, len(header_list)): if i == 0: if len(header_list[i].split(' ')) == 3: header_dict['method'], header_dict['url'], header_dict['protocol'] = header_list[i].split(' ') else: k, v = header_list[i].split(':', 1) header_dict[k] = v.strip() return header_dict sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) sock.bind(('127.0.0.1', 8000)) sock.listen(5) while True: conn, address = sock.accept() print('有链接过来。。。') data = conn.recv(1024) headers = get_headers(data) magic_string = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11' str_concatenate = headers['Sec-WebSocket-Key']+magic_string swa = base64.b64encode(hashlib.sha1(bytes(headers['Sec-WebSocket-Key']+magic_string,encoding='utf-8')).digest()) response_tpl = "HTTP/1.1 101 Switching Protocols\r\n" \ "Upgrade:websocket\r\n" \ "Connection: Upgrade\r\n" \ "Sec-WebSocket-Accept: %s\r\n" \ "WebSocket-Location: ws://%s%s\r\n\r\n" print(response_tpl) response = response_tpl %(swa.decode('utf-8'),headers['Host'],headers['url']) conn.send(bytes(response,encoding='utf-8')) conn.close()
服务端解析客户端发的数据【解包】
客户端发来的 Frame Format
0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-------+-+-------------+-------------------------------+ |F|R|R|R| opcode|M| Payload len | Extended payload length | |I|S|S|S| (4) |A| (7) | (16/64) | |N|V|V|V| |S| | (if payload len==126/127) | | |1|2|3| |K| | | +-+-+-+-+-------+-+-------------+ - - - - - - - - - - - - - - - + | Extended payload length continued, if payload len == 127 | + - - - - - - - - - - - - - - - +-------------------------------+ | |Masking-key, if MASK set to 1 | +-------------------------------+-------------------------------+ | Masking-key (continued) | Payload Data | +-------------------------------- - - - - - - - - - - - - - - - + : Payload Data continued ... : + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + | Payload Data continued ... | +---------------------------------------------------------------+
官方解释:
Client: FIN=1, opcode=0x1, msg="hello" Server: (process complete message immediately) Hi. Client: FIN=0, opcode=0x1, msg="and a" Server: (listening, new message containing text started) Client: FIN=0, opcode=0x0, msg="happy new" Server: (listening, payload concatenated to previous message) Client: FIN=1, opcode=0x0, msg="year!" Server: (process complete message) Happy new year to you too!
客户端
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <input type="text" id="input_msg"> <button id="send_msg">发送消息</button> <script> var socket = new WebSocket("ws://127.0.0.1:8000/chat"); var send_btn = document.getElementById('send_msg'); var input = document.getElementById('input_msg'); send_btn.onclick = function() { console.log(input.value); if(1 == socket.readyState){ socket.send(input.value); input.value = ""; }else { alert('连接尚未建立'); } } </script> </body> </html>
服务端
import socket import hashlib import base64 def get_headers(data): """ 将请求头格式化成字典 :param data: :return: """ header_dict = {} data = str(data, encoding='utf-8') header, body = data.split('\r\n\r\n', 1) header_list = header.split('\r\n') for i in range(0, len(header_list)): if i == 0: if len(header_list[i].split(' ')) == 3: header_dict['method'], header_dict['url'], header_dict['protocol'] = header_list[i].split(' ') else: k, v = header_list[i].split(':', 1) header_dict[k] = v.strip() return header_dict sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) sock.bind(('127.0.0.1', 8000)) sock.listen(5) conn, address = sock.accept() print('有链接过来。。。') data = conn.recv(1024) headers = get_headers(data) magic_string = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11' str_concatenate = headers['Sec-WebSocket-Key']+magic_string swa = base64.b64encode(hashlib.sha1(bytes(headers['Sec-WebSocket-Key']+magic_string,encoding='utf-8')).digest()) response_tpl = "HTTP/1.1 101 Switching Protocols\r\n" \ "Upgrade:websocket\r\n" \ "Connection: Upgrade\r\n" \ "Sec-WebSocket-Accept: %s\r\n" \ "WebSocket-Location: ws://%s%s\r\n\r\n" response = response_tpl %(swa.decode('utf-8'),headers['Host'],headers['url']) conn.send(bytes(response,encoding='utf-8')) while True: info = conn.recv(8096) payload_len = info[1] & 127 if payload_len == 126: extend_payload_len = info[2:4] mask = info[4:8] decoded = info[8:] elif payload_len == 127: extend_payload_len = info[2:10] mask = info[10:14] decoded = info[14:] else: extend_payload_len = None mask = info[2:6] decoded = info[6:] bytes_list = bytearray() for i in range(len(decoded)): chunk = decoded[i] ^ mask[i % 4] bytes_list.append(chunk) # body = str(bytes_list, encoding='utf-8') body = bytes_list.decode('utf-8') print(body) conn.close()
服务端给客户端发送数据【封包】
def send_msg(conn, msg_bytes): """ WebSocket服务端向客户端发送消息 :param conn: 客户端连接到服务器端的socket对象,即: conn,address = socket.accept() :param msg_bytes: 向客户端发送的字节 :return: """ import struct token = b"\x81" # 即 10000001,FIN置为1,opcode置为0x1 length = len(msg_bytes) if length < 126: token += struct.pack("B", length) elif length <= 0xFFFF: token += struct.pack("!BH", 126, length) else: token += struct.pack("!BQ", 127, length) msg = token + msg_bytes conn.send(msg) return True
服务端封包的时候不需要加密,即没有 MASK 字段。
但是需要注意length的判断和字节序的问题。
基于Python简单实现的WebSocket示例
服务端:
import socket import base64 import hashlib def get_headers(data): """ 将请求头格式化成字典 :param data: :return: """ header_dict = {} data = str(data, encoding='utf-8') header, body = data.split('\r\n\r\n', 1) header_list = header.split('\r\n') for i in range(0, len(header_list)): if i == 0: if len(header_list[i].split(' ')) == 3: header_dict['method'], header_dict['url'], header_dict['protocol'] = header_list[i].split(' ') else: k, v = header_list[i].split(':', 1) header_dict[k] = v.strip() return header_dict def send_msg(conn, msg_bytes): """ WebSocket服务端向客户端发送消息 :param conn: 客户端连接到服务器端的socket对象,即: conn,address = socket.accept() :param msg_bytes: 向客户端发送的字节 :return: """ import struct token = b"\x81" # 即 10000001,FIN置为1,opcode置为0x1 length = len(msg_bytes) if length < 126: token += struct.pack("B", length) elif length <= 0xFFFF: # Read the next 16 bits and interpret those as an unsigned integer. token += struct.pack("!BH", 126, length) else: # Read the next 64 bits and interpret those as an unsigned integer. token += struct.pack("!BQ", 127, length) msg = token + msg_bytes conn.send(msg) return True def get_conn(ip='127.0.0.1',port=80): """ 准备接收客户端的请求并建立连接 :param ip: 绑定的ip :param port: 监听的端口 :return: """ sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) sock.bind((ip, port)) sock.listen(5) conn, address = sock.accept() print("有连接到来...") data = conn.recv(1024) headers = get_headers(data) magic_string = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11' str_completed = headers['Sec-WebSocket-Key'] + magic_string swa = base64.b64encode(hashlib.sha1(bytes(str_completed, encoding='utf-8')).digest()) response_tpl = "HTTP/1.1 101 Switching Protocols\r\n" \ "Upgrade:websocket\r\n" \ "Connection: Upgrade\r\n" \ "Sec-WebSocket-Accept: %s\r\n" \ "WebSocket-Location: ws://%s%s\r\n\r\n" response = response_tpl % (swa.decode('utf-8'), headers['Host'], headers['url']) conn.send(bytes(response, encoding='utf-8')) return sock,conn def close(sock): """ 关闭sock连接 :param sock: :return: """ sock.close() def run(): """ 消息循环 :return: """ sock,conn = get_conn() while True: try: info = conn.recv(8096) except Exception as e: info = None if not info: break # 位运算得到第二个字节后7个bit的值 payload_len = info[1] & 127 if payload_len == 126: extend_payload_len = info[2:4] mask = info[4:8] decoded = info[8:] elif payload_len == 127: extend_payload_len = info[2:10] mask = info[10:14] decoded = info[14:] else: extend_payload_len = None mask = info[2:6] decoded = info[6:] bytes_list = bytearray() # DECODED for i in range(len(decoded)): chunk = decoded[i] ^ mask[i % 4] bytes_list.append(chunk) body = str(bytes_list, encoding='utf-8') print("Client: %s" % body) send_msg(conn, ("服务端已收到: %s" % body).encode('utf-8')) close(sock) if __name__ == '__main__': run()
客户端:
<!DOCTYPE html> <html> <head lang="en"> <meta charset="UTF-8"> <title></title> </head> <body> <div> <input type="text" id="txt"/> <input type="button" id="btn" value="提交" onclick="sendMsg();"/> <input type="button" id="close" value="关闭连接" onclick="closeConn();"/> </div> <div id="content"></div> <script type="text/javascript"> var socket = new WebSocket("ws://127.0.0.1:80/chatsocket"); socket.onopen = function () { /* 与服务器端连接成功后,自动执行 */ var newTag = document.createElement('div'); newTag.innerHTML = "【连接成功】"; document.getElementById('content').appendChild(newTag); }; socket.onmessage = function (event) { /* 服务器端向客户端发送数据时,自动执行 */ var response = event.data; var newTag = document.createElement('div'); newTag.innerHTML = response; document.getElementById('content').appendChild(newTag); }; socket.onclose = function (event) { /* 服务器端主动断开连接时,自动执行 */ var newTag = document.createElement('div'); newTag.innerHTML = "【关闭连接】"; document.getElementById('content').appendChild(newTag); }; function sendMsg() { var txt = document.getElementById('txt'); socket.send(txt.value); txt.value = ""; } function closeConn() { socket.close(); var newTag = document.createElement('div'); newTag.innerHTML = "【关闭连接】"; document.getElementById('content').appendChild(newTag); } </script> </body> </html>
基于Tornado框架实现Web聊天室
示例来自:http://www.cnblogs.com/wupeiqi/articles/6558766.html
import uuid import json import tornado.ioloop import tornado.web import tornado.websocket class IndexHandler(tornado.web.RequestHandler): def get(self): self.render('index.html') class ChatHandler(tornado.websocket.WebSocketHandler): # 用户存储当前聊天室用户 waiters = set() # 用于存储历时消息 messages = [] def open(self): """ 客户端连接成功时,自动执行 :return: """ ChatHandler.waiters.add(self) uid = str(uuid.uuid4()) self.write_message(uid) for msg in ChatHandler.messages: content = self.render_string('message.html', **msg) self.write_message(content) def on_message(self, message): """ 客户端连发送消息时,自动执行 :param message: :return: """ msg = json.loads(message) ChatHandler.messages.append(message) for client in ChatHandler.waiters: content = client.render_string('message.html', **msg) client.write_message(content) def on_close(self): """ 客户端关闭连接时,,自动执行 :return: """ ChatHandler.waiters.remove(self) def run(): settings = { 'template_path': 'templates', 'static_path': 'static', } application = tornado.web.Application([ (r"/", IndexHandler), (r"/chat", ChatHandler), ], **settings) application.listen(8888) tornado.ioloop.IOLoop.instance().start() if __name__ == "__main__": run()
index.html
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Python聊天室</title> </head> <body> <div> <input type="text" id="txt"/> <input type="button" id="btn" value="提交" onclick="sendMsg();"/> <input type="button" id="close" value="关闭连接" onclick="closeConn();"/> </div> <div id="container" style="border: 1px solid #dddddd;margin: 20px;min-height: 500px;"> </div> <script src="/static/jquery-2.1.4.min.js"></script> <script type="text/javascript"> $(function () { wsUpdater.start(); }); var wsUpdater = { socket: null, uid: null, start: function() { var url = "ws://127.0.0.1:8888/chat"; wsUpdater.socket = new WebSocket(url); wsUpdater.socket.onmessage = function(event) { console.log(event); if(wsUpdater.uid){ wsUpdater.showMessage(event.data); }else{ wsUpdater.uid = event.data; } } }, showMessage: function(content) { $('#container').append(content); } }; function sendMsg() { var msg = { uid: wsUpdater.uid, message: $("#txt").val() }; wsUpdater.socket.send(JSON.stringify(msg)); } </script> </body> </html>
参考:http://www.cnblogs.com/wupeiqi/articles/6558766.html
参考:https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API/Writing_WebSocket_servers
RFC 6455:https://tools.ietf.org/html/rfc6455
WebSocket+Flask实现的实时投票和实时通知示例
''' pip install gevent-websocket ''' from flask import Flask,render_template,request,session,redirect,jsonify import uuid from geventwebsocket.handler import WebSocketHandler from gevent.pywsgi import WSGIServer import json app = Flask(__name__) app.secret_key = 'wnclwespcqwlkjaytcw' USERS = { '1':{'name':'小明','count':0}, '2':{'name':'小强','count':0}, '3':{'name':'小刚','count':0}, } @app.before_request def before_request(): allow_url = ['login','notify'] if request.endpoint in allow_url: return None user_info = session.get('user_info') if user_info: return None return redirect('/login') @app.route('/login',methods=['GET','POST']) def login(): if request.method == "GET": return render_template('login.html') else: uid = str(uuid.uuid4()) session['user_info'] = {'id':uid,'name':request.form.get('user')} return redirect('/index') @app.route('/index') def index(): return render_template('index.html',users=USERS) # 用来保存全部WS链接 WS_DICT = {} @app.route('/notify') def notify(): data = {'msg': '有新工单到来,请及时处理!', 'type': 'notify'} for k, v in WS_DICT.items(): # 3. 向全部存活的客户端推送消息 v.send(json.dumps(data)) return "消息已推送" @app.route('/message') def message(): if request.environ.get('wsgi.websocket'): # 根据 'wsgi.websocket' 这个字段是否为空来判断来源是 websocket 还是 http ws = request.environ['wsgi.websocket'] if not ws: return "请使用WebSocket协议" # 1. 刚连接成功 uid = session.get('user_info').get('id') WS_DICT[uid] = ws print('有连接到来, Name: %s from: %s' % (session['user_info'],ws)) print(WS_DICT) from geventwebsocket.websocket import WebSocket while True: # 2. 等待用户发送消息,并接受 message = ws.receive() # 如果客户端关闭浏览器,那么就会收到一个None,即 message=None if not message: del WS_DICT[uid] break old = USERS[message]['count'] new = old + 1 USERS[message]['count'] = new data = {'user':message,'count':new,'type':'vote'} for k,v in WS_DICT.items(): # 3. 向全部存活的客户端推送消息 v.send(json.dumps(data)) return "Connected!" if __name__ == '__main__': http_server = WSGIServer(('127.0.0.1', 8000), app, handler_class=WebSocketHandler) http_server.serve_forever()
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <form method="post" novalidate> <input type="text" name="user"> <input type="submit" value="提交"> </form> </body> </html>
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>Title</title> </head> <body> <h1>基于WebSocket+Flask的投票系统</h1> <a onclick="closeConn();" href="#">关闭连接</a> <!-- <a onclick="createConn();" href="">创建连接</a> 这样写会导致无法保持websocket连接 --> <a onclick="createConn();" href="#">创建连接</a> <ul> {% for k,v in users.items() %} <li style="cursor:pointer;" id="user_{{k}}" ondblclick="vote('{{k}}')">{{v.name}} <span>{{v.count}}</span> </li> {% endfor %} </ul> <script src="{{ url_for('static',filename='jquery-3.3.1.min.js')}}"></script> <script> var socket = null; function socketInit() { socket.onopen = function () { /* 与服务器端连接成功后,自动执行 */ alert('与服务器端握手成功,可以开始投票。'); }; socket.onmessage = function (event) { /* 服务器端向客户端发送数据时,自动执行 */ var response = JSON.parse(event.data); // {'user':1,'count':new,'type':'vote'} if('vote' == response['type']) { var nid = '#user_' + response.user; $(nid).find('span').text(response.count); } else if('notify' == response['type']) { alert(response['msg']); } }; socket.onclose = function (event) { /* 服务器端主动断开连接时,自动执行 */ alert('服务器端已经断开WebSocket链接。'); }; } function vote(id) { if(socket != null) { socket.send(id); } else { alert('请先建立WebSocket链接'); } } function closeConn() { socket.close() } function createConn() { socket = new WebSocket("ws://127.0.0.1:8000/message"); socketInit(); } </script> </body> </html>
作者:Standby — 一生热爱名山大川、草原沙漠,还有我们小郭宝贝!
出处:http://www.cnblogs.com/standby/
本文版权归作者和博客园共有,欢迎转载,但未经作者同意必须保留此段声明,且在文章页面明显位置给出原文连接,否则保留追究法律责任的权利。
出处:http://www.cnblogs.com/standby/
本文版权归作者和博客园共有,欢迎转载,但未经作者同意必须保留此段声明,且在文章页面明显位置给出原文连接,否则保留追究法律责任的权利。