Question

怎样判断websocket是否断开 有没有对应的api （我用的是Django 和Python语言）

当客户的断开连接 我需要在服务端处理 一些动作 但是服务端怎么知道连接已经断开 Java中是有对应的API的 在Python中有吗？ 要在Django框架中使用。

Answer 1

# coding:utf-8
import os
import struct
import base64
import hashlib
import socket
import threading
import paramiko

def get_ssh(ip, user, pwd):
try:
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(ip, 22, user, pwd, timeout=15)
return ssh
except Exception, e:
print e
return "False"

def recv_data(conn): # 服务器解析浏览器发送的信息
try:
all_data = conn.recv(1024)
if not len(all_data):
return False
except:
pass
else:
code_len = ord(all_data[1]) & 127
if code_len == 126:
masks = all_data[4:8]
data = all_data[8:]
elif code_len == 127:
masks = all_data[10:14]
data = all_data[14:]
else:
masks = all_data[2:6]
data = all_data[6:]
raw_str = ""
i = 0
for d in data:
raw_str += chr(ord(d) ^ ord(masks[i % 4]))
i += 1
return raw_str

def send_data(conn, data): # 服务器处理发送给浏览器的信息
if data:
data = str(data)
else:
return False
token = "\x81"
length = len(data)
if length < 126:
token += struct.pack("B", length) # struct为Python中处理二进制数的模块，二进制流为C，或网络流的形式。
elif length <= 0xFFFF:
token += struct.pack("!BH", 126, length)
else:
token += struct.pack("!BQ", 127, length)
data = '%s%s' % (token, data)
conn.send(data)
return True

def handshake(conn, address, thread_name):
headers = {}
shake = conn.recv(1024)
if not len(shake):
return False

print ('%s : Socket start handshaken with %s:%s' % (thread_name, address[0], address[1]))
header, data = shake.split('\r\n\r\n', 1)
for line in header.split('\r\n')[1:]:
key, value = line.split(': ', 1)
headers[key] = value

if 'Sec-WebSocket-Key' not in headers:
print ('%s : This socket is not websocket, client close.' % thread_name)
conn.close()
return False

MAGIC_STRING = '258EAFA5-E914-47DA-95CA-C5AB0DC85B11'
HANDSHAKE_STRING = "HTTP/1.1 101 Switching Protocols\r\n" \
"Upgrade:websocket\r\n" \
"Connection: Upgrade\r\n" \
"Sec-WebSocket-Accept: {1}\r\n" \
"WebSocket-Origin: {2}\r\n" \
"WebSocket-Location: ws://{3}/\r\n\r\n"

sec_key = headers['Sec-WebSocket-Key']
res_key = base64.b64encode(hashlib.sha1(sec_key + MAGIC_STRING).digest())
str_handshake = HANDSHAKE_STRING.replace('{1}', res_key).replace('{2}', headers['Origin']).replace('{3}', headers['Host'])
conn.send(str_handshake)
print ('%s : Socket handshaken with %s:%s success' % (thread_name, address[0], address[1]))
print 'Start transmitting data...'
print '- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -'
return True

def dojob(conn, address, thread_name):
handshake(conn, address, thread_name) # 握手
conn.setblocking(0) # 设置socket为非阻塞

ssh = get_ssh('192.168.1.1', 'root', '123456') # 连接远程服务器
ssh_t = ssh.get_transport()
chan = ssh_t.open_session()
chan.setblocking(0) # 设置非阻塞
chan.exec_command('tail -f /var/log/messages')

while True:
clientdata = recv_data(conn)
if clientdata is not None and 'quit' in clientdata: # 但浏览器点击stop按钮或close按钮时，断开连接
print ('%s : Socket close with %s:%s' % (thread_name, address[0], address[1]))
send_data(conn, 'close connect')
conn.close()
break
while True:
while chan.recv_ready():
clientdata1 = recv_data(conn)
if clientdata1 is not None and 'quit' in clientdata1:
print ('%s : Socket close with %s:%s' % (thread_name, address[0], address[1]))
send_data(conn, 'close connect')
conn.close()
break
log_msg = chan.recv(10000).strip() # 接收日志信息
print log_msg
send_data(conn, log_msg)
if chan.exit_status_ready():
break
clientdata2 = recv_data(conn)
if clientdata2 is not None and 'quit' in clientdata2:
print ('%s : Socket close with %s:%s' % (thread_name, address[0], address[1]))
send_data(conn, 'close connect')
conn.close()
break
break

def ws_service():

index = 1
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(("127.0.0.1", 12345))
sock.listen(100)

print ('\r\n\r\nWebsocket server start, wait for connect!')
print '- - - - - - - - - - - - - - - - - - - - - - - - - - - - - -'
while True:
connection, address = sock.accept()
thread_name = 'thread_%s' % index
print ('%s : Connection from %s:%s' % (thread_name, address[0], address[1]))
t = threading.Thread(target=dojob, args=(connection, address, thread_name))
t.start()
index += 1

ws_service()