WebSocket学习
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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>
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