亚洲免费在线-亚洲免费在线播放-亚洲免费在线观看-亚洲免费在线观看视频-亚洲免费在线看-亚洲免费在线视频

使用Python的Twisted框架編寫簡單的網(wǎng)絡(luò)客戶端

系統(tǒng) 1521 0

Protocol
? 和服務(wù)器一樣,也是通過該類來實現(xiàn)。先看一個簡短的例程:

            
from twisted.internet.protocol import Protocol
from sys import stdout

class Echo(Protocol):
  def dataReceived(self, data):
    stdout.write(data)


          

在本程序中,只是簡單的將獲得的數(shù)據(jù)輸出到標準輸出中來顯示,還有很多其他的事件沒有作出任何響應(yīng),下面
有一個回應(yīng)其他事件的例子:

            
from twisted.internet.protocol import Protocol

class WelcomeMessage(Protocol):
  def connectionMade(self):
    self.transport.write("Hello server, I am the client!/r/n")
    self.transport.loseConnection()


          

本協(xié)議連接到服務(wù)器,發(fā)送了一個問候消息,然后關(guān)閉了連接。
connectionMade事件通常被用在建立連接的事件發(fā)生時觸發(fā)。關(guān)閉連接的時候會觸發(fā)connectionLost事件函數(shù)

(Simple, single-use clients)簡單的單用戶客戶端
? 在許多情況下,protocol僅僅是需要連接服務(wù)器一次,并且代碼僅僅是要獲得一個protocol連接的實例。在
這樣的情況下,twisted.internet.protocol.ClientCreator提供了一個恰當?shù)腁PI

            
from twisted.internet import reactor
from twisted.internet.protocol import Protocol, ClientCreator

class Greeter(Protocol):
  def sendMessage(self, msg):
    self.transport.write("MESSAGE %s/n" % msg)

def gotProtocol(p):
  p.sendMessage("Hello")
  reactor.callLater(1, p.sendMessage, "This is sent in a second")
  reactor.callLater(2, p.transport.loseConnection)

c = ClientCreator(reactor, Greeter)
c.connectTCP("localhost", 1234).addCallback(gotProtocol)


          


ClientFactory(客戶工廠)
? ClientFactory負責創(chuàng)建Protocol,并且返回相關(guān)事件的連接狀態(tài)。這樣就允許它去做像連接發(fā)生錯誤然后
重新連接的事情。這里有一個ClientFactory的簡單例子使用Echo協(xié)議并且打印當前的連接狀態(tài)

            
from twisted.internet.protocol import Protocol, ClientFactory
from sys import stdout

class Echo(Protocol):
  def dataReceived(self, data):
    stdout.write(data)

class EchoClientFactory(ClientFactory):
  def startedConnecting(self, connector):
    print 'Started to connect.'
  
  def buildProtocol(self, addr):
    print 'Connected.'
    return Echo()
  
  def clientConnectionLost(self, connector, reason):
    print 'Lost connection. Reason:', reason
  
  def clientConnectionFailed(self, connector, reason):
    print 'Connection failed. Reason:', reason


          

要想將EchoClientFactory連接到服務(wù)器,可以使用下面代碼:

            
from twisted.internet import reactor
reactor.connectTCP(host, port, EchoClientFactory())
reactor.run()

          

注意:clientConnectionFailed是在Connection不能被建立的時候調(diào)用,clientConnectionLost是在連接關(guān)閉的時候被調(diào)用,兩個是有區(qū)別的。


Reconnection(重新連接)
? 許多時候,客戶端連接可能由于網(wǎng)絡(luò)錯誤經(jīng)常被斷開。一個重新建立連接的方法是在連接斷開的時候調(diào)用

connector.connect()方法。

            
from twisted.internet.protocol import ClientFactory

class EchoClientFactory(ClientFactory):
  def clientConnectionLost(self, connector, reason):
    connector.connect()


          

?? connector是connection和protocol之間的一個接口被作為第一個參數(shù)傳遞給clientConnectionLost,

factory能調(diào)用connector.connect()方法重新進行連接
?? 然而,許多程序在連接失敗和連接斷開進行重新連接的時候使用ReconnectingClientFactory函數(shù)代替這個

函數(shù),并且不斷的嘗試重新連接。這里有一個Echo Protocol使用ReconnectingClientFactory的例子:

            
from twisted.internet.protocol import Protocol, ReconnectingClientFactory
from sys import stdout

class Echo(Protocol):
  def dataReceived(self, data):
    stdout.write(data)

class EchoClientFactory(ReconnectingClientFactory):
  def startedConnecting(self, connector):
    print 'Started to connect.'

  def buildProtocol(self, addr):
    print 'Connected.'
    print 'Resetting reconnection delay'
    self.resetDelay()
    return Echo()

  def clientConnectionLost(self, connector, reason):
    print 'Lost connection. Reason:', reason
    ReconnectingClientFactory.clientConnectionLost(self, connector, reason)

  def clientConnectionFailed(self, connector, reason):
    print 'Connection failed. Reason:', reason
    ReconnectingClientFactory.clientConnectionFailed(self, connector,reason)


          


A Higher-Level Example: ircLogBot
上面的所有例子都非常簡單,下面是一個比較復(fù)雜的例子來自于doc/examples目錄

            
# twisted imports
from twisted.words.protocols import irc
from twisted.internet import reactor, protocol
from twisted.python import log

# system imports
import time, sys


class MessageLogger:
  """
  An independent logger class (because separation of application
  and protocol logic is a good thing).
  """
  def __init__(self, file):
    self.file = file

  def log(self, message):
    """Write a message to the file."""
    timestamp = time.strftime("[%H:%M:%S]", time.localtime(time.time()))
    self.file.write('%s %s/n' % (timestamp, message))
    self.file.flush()

  def close(self):
    self.file.close()


class LogBot(irc.IRCClient):
  """A logging IRC bot."""

  nickname = "twistedbot"

  def connectionMade(self):
    irc.IRCClient.connectionMade(self)
    self.logger = MessageLogger(open(self.factory.filename, "a"))
    self.logger.log("[connected at %s]" %
            time.asctime(time.localtime(time.time())))

  def connectionLost(self, reason):
    irc.IRCClient.connectionLost(self, reason)
    self.logger.log("[disconnected at %s]" %
            time.asctime(time.localtime(time.time())))
    self.logger.close()


  # callbacks for events

  def signedOn(self):
    """Called when bot has succesfully signed on to server."""
    self.join(self.factory.channel)

  def joined(self, channel):
    """This will get called when the bot joins the channel."""
    self.logger.log("[I have joined %s]" % channel)

  def privmsg(self, user, channel, msg):
    """This will get called when the bot receives a message."""
    user = user.split('!', 1)[0]
    self.logger.log("<%s> %s" % (user, msg))

    # Check to see if they're sending me a private message
    if channel == self.nickname:
      msg = "It isn't nice to whisper! Play nice with the group."
      self.msg(user, msg)
      return

    # Otherwise check to see if it is a message directed at me
    if msg.startswith(self.nickname + ":"):
      msg = "%s: I am a log bot" % user
      self.msg(channel, msg)
      self.logger.log("<%s> %s" % (self.nickname, msg))

  def action(self, user, channel, msg):
    """This will get called when the bot sees someone do an action."""
    user = user.split('!', 1)[0]
    self.logger.log("* %s %s" % (user, msg))

  # irc callbacks

  def irc_NICK(self, prefix, params):
    """Called when an IRC user changes their nickname."""
    old_nick = prefix.split('!')[0]
    new_nick = params[0]
    self.logger.log("%s is now known as %s" % (old_nick, new_nick))


class LogBotFactory(protocol.ClientFactory):
  """A factory for LogBots.

  A new protocol instance will be created each time we connect to the server.
  """

  # the class of the protocol to build when new connection is made
  protocol = LogBot

  def __init__(self, channel, filename):
    self.channel = channel
    self.filename = filename

  def clientConnectionLost(self, connector, reason):
    """If we get disconnected, reconnect to server."""
    connector.connect()

  def clientConnectionFailed(self, connector, reason):
    print "connection failed:", reason
    reactor.stop()


if __name__ == '__main__':
  # initialize logging
  log.startLogging(sys.stdout)

  # create factory protocol and application
  f = LogBotFactory(sys.argv[1], sys.argv[2])

  # connect factory to this host and port
  reactor.connectTCP("irc.freenode.net", 6667, f)

  # run bot
  reactor.run()


          

ircLogBot.py 連接到了IRC服務(wù)器,加入了一個頻道,并且在文件中記錄了所有的通信信息,這表明了在斷開連接進行重新連接的連接級別的邏輯以及持久性數(shù)據(jù)是被存儲在Factory的。

Persistent Data in the Factory
? 由于Protocol在每次連接的時候重建,客戶端需要以某種方式來記錄數(shù)據(jù)以保證持久化。就好像日志機器人一樣他需要知道那個那個頻道正在登陸,登陸到什么地方去。

            
from twisted.internet import protocol
from twisted.protocols import irc

class LogBot(irc.IRCClient):

  def connectionMade(self):
    irc.IRCClient.connectionMade(self)
    self.logger = MessageLogger(open(self.factory.filename, "a"))
    self.logger.log("[connected at %s]" %
            time.asctime(time.localtime(time.time())))
  
  def signedOn(self):
    self.join(self.factory.channel)

  
class LogBotFactory(protocol.ClientFactory):
  
  protocol = LogBot
  
  def __init__(self, channel, filename):
    self.channel = channel
    self.filename = filename


          

當protocol被創(chuàng)建之后,factory會獲得他本身的一個實例的引用。然后,就能夠在factory中存在他的屬性。

更多的信息:
? 本文檔講述的Protocol類是IProtocol的子類,IProtocol方便的被應(yīng)用在大量的twisted應(yīng)用程序中。要學習完整的 IProtocol接口,請參考API文檔IProtocol.
? 在本文檔一些例子中使用的trasport屬性提供了ITCPTransport接口,要學習完整的接口,請參考API文檔ITCPTransport
? 接口類是指定對象有什么方法和屬性以及他們的表現(xiàn)形式的一種方法。參考 Components: Interfaces and Adapters文檔


更多文章、技術(shù)交流、商務(wù)合作、聯(lián)系博主

微信掃碼或搜索:z360901061

微信掃一掃加我為好友

QQ號聯(lián)系: 360901061

您的支持是博主寫作最大的動力,如果您喜歡我的文章,感覺我的文章對您有幫助,請用微信掃描下面二維碼支持博主2元、5元、10元、20元等您想捐的金額吧,狠狠點擊下面給點支持吧,站長非常感激您!手機微信長按不能支付解決辦法:請將微信支付二維碼保存到相冊,切換到微信,然后點擊微信右上角掃一掃功能,選擇支付二維碼完成支付。

【本文對您有幫助就好】

您的支持是博主寫作最大的動力,如果您喜歡我的文章,感覺我的文章對您有幫助,請用微信掃描上面二維碼支持博主2元、5元、10元、自定義金額等您想捐的金額吧,站長會非常 感謝您的哦!!!

發(fā)表我的評論
最新評論 總共0條評論
主站蜘蛛池模板: 国产精品分类视频分类一区 | 精品无人乱码区1区2区3区 | 色一情一乱一伦麻豆 | 狼人综合干伊人 | 亚洲国产成人精品区 | 69福利网| 久久久久久久久网站 | 日本亚洲成高清一区二区三区 | 欧美成人午夜视频在线观看 | 91青青青国产在观免费影视 | 久艹在线播放 | 四虎网站在线播放 | 免费区欧美一级毛片精品 | 91久久精一区二区三区大全 | 玖玖国产在线观看 | 欧美成人性毛片免费版 | 七月婷婷精品视频在线观看 | 成人短视频在线观看免费 | 日韩欧美二区在线观看 | 色天使色婷婷丁香久久综合 | 久久精品国产精品亚洲综合 | 色视频网站在线观看 | 欧美日韩中文视频 | 七七久久综合 | 99视频有精品视频免费观看 | 国产真实强j视频在线观看 国产真实偷乱视频在线观看 | 亚洲国产精品日韩一线满 | 亚洲色图插插插 | 大杳焦伊人久久综合热 | 国产精品久久久久久久网站 | 狠狠色欧美亚洲狠狠色五 | 久久天天躁狠狠躁狠狠躁 | 免费观看成人久久网免费观看 | 欧美激情视频网址 | 亚洲专区欧美专区 | 亚州毛片 | 欧美日韩在大午夜爽爽影院 | 99re66热这里只有精品首页 | 久久久久欧美精品网站 | 日本aaaa毛片在线看 | 国产精品久久久久久福利 |