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。
