python实现ftp文件传输系统(案例分析)

最近做了一个简单的文件传输系统，基于ftp协议，使用python语言开发，虽然python里面已经有ftplib模块，可以很容易的实现ftp服务器。这次我使用的是socket实现client与ftp server之间的通讯和文件传输，client另起一个flask服务器，用于用户在浏览器端的交互。系统实现的功能有：用户登录注册，用户查看ftp服务器端文件和下载上传删除操作，支持多进程、多用户。

一，登录注册

该项目使用的是mongo数据库，其实用户登录注册功能很好实现，没有什么技术细节，这里就略过了。数据库管理代码如下：

import pymongo
from pymongo.collection import Collection
class DBManager(object):
 def __init__(self):
  client = pymongo.MongoClient(\"mongodb://localhost:27017/\")
  self.db = client[\"FTPDB\"]
  self.users = self.db[\'user\']
 #保存用户登录信息
 def saveUserInfo(self,account,password):
  users = self.users.find()
  for item in users:
   accountDB = item[\'account\']
   if accountDB == account:
    return \"false\"
  data = []
  userInfo = {}
  userInfo[\'account\'] = account
  userInfo[\'password\'] = password
  data.append(userInfo)
  collection = Collection(self.db,\"user\")
  collection.insert(data)
  return \"true\"
 def confirmUserLoginInfo(self,account,password):
  users = self.users.find()
  \'\'\'
   result状态： 1：表示初始状态，即不存在用户
      2：表示存在该用户、密码不正确
      3：验证成功
  \'\'\'
  result = 1
  for item in users:
   accountDB = item[\'account\']
   passwordDB = item[\'password\']
   if accountDB == account:
    if passwordDB == password:
     result = 3
    else:
     result = 2
  return result

前端注册js代码如下：

function register() {
 account = $(\"#account\").val();
 password = $(\"#password\").val();
 confirmPassword = $(\"#confirmPassword\").val();
 if(account == null || password == null || confirmPassword == null){
  alert(\"请先输入必要信息\")
  return;
 }
 if(password != confirmPassword){
  alert(\"密码不一致\");
  return;
 }
 var request = {
  type:\"register\",
  account:account,
  password:password
 }
 sendData(\"http://localhost:8080/register\",request)
}
//向服务器发送数据
function sendData(url,json) {
 $.ajax({
  url: url, //请求的url地址
  dataType: \"json\", //返回格式为json
  async: true, //请求是否异步，默认为异步，这也是ajax重要特性
  data: json, //参数值
  type: \"post\", //请求方式
  success:function(data){
   //alert(data)
   if(data.toString() == \"false\"){
    alert(\"用户名已存在\");
   }else{
    window.location.href = \"http://localhost:8080/index\";
   }
  },
  error:function (error) {
   console.log(error);
  }
 });
}

二，文件管理(文件查看、删除、上传、下载)

客户端与服务器端约定命令格式，服务器通过解析客户端命令来执行操作。

server.py
from socket import *
import os,sys
import signal
import time
# 全局变量
HOST = \'0.0.0.0\'
PORT = 8686
ADDR = (HOST,PORT)
FILE_PATH = \'../serverFiles/\'
# 处理僵尸进程
signal.signal(signal.SIGCHLD,signal.SIG_IGN)
# 服务端功能类
class Server(object):
 def __init__(self):
  self.connfd = \"\"
 def do_list(self,account):
  # 获取文件列表
  file_list = os.listdir(FILE_PATH+account)
  if not file_list:
   self.connfd.send(\"服务器文件库为空\".encode())
   return
  else:
   self.connfd.send(b\"OK\")
   time.sleep(0.1)
  files = \"\"
  for file in file_list:
   if file[0] != \'.\' and os.path.isfile(FILE_PATH + account +\"/\"+ file):
    files += file + \'#\'
  self.connfd.send(files.encode())
 def delete(self,accout,fileName):
  os.remove(FILE_PATH + accout + \"/\" + fileName)
  self.connfd.send(b\"OK\")
  time.sleep(0.1)
 def do_get(self,account,filename):
  try:
   fd = open(FILE_PATH + account +\"/\"+ filename,\'rb\')
  except IOError:
   self.connfd.send(\"文件不存在\".encode())
   return
  else:
   #print(\"发送OK\")
   self.connfd.send(b\'OK\')
   time.sleep(0.1)
  # 发送文件内容
  while True:
   data = fd.read(1024)
   if not data:
    time.sleep(0.1)
    self.connfd.send(b\'##\')
    break
   #print(\"正在发送数据\")
   self.connfd.send(data)
  fd.close()
 def do_put(self,account,filename):
  if os.path.exists(FILE_PATH + account +\"/\"+ filename):
   self.connfd.send(\'该文件已存在\'.encode())
   return
  fd = open(FILE_PATH + account +\"/\"+ filename,\'wb\')
  self.connfd.send(b\'OK\')
  # 接收文件内容
  while True:
   data = self.connfd.recv(1024)
   if data == b\'**\':
    break
   fd.write(data)
  fd.close()
 def socket_tcp(self):
  s = socket()
  s.setsockopt(SOL_SOCKET,SO_REUSEADDR,True)
  s.bind(ADDR)
  s.listen(5)
  print(\"Listen the port 8686...\")
  return s
 def do_request(self,connfd):
  self.connfd = connfd
  while True:
   data = connfd.recv(1024).decode()
   datas = data.split(\' \')
   if not data or datas[1] == \'QUIT@#\':
    connfd.close()
    return
   elif datas[1] == \"LIST@#\":
    #print(\"list\")
    self.do_list(datas[0])
   elif datas[1] == \'GET@#\':
    filename = datas[-1]
    self.do_get(datas[0],filename)
   elif datas[1] == \'PUT@#\':
    filename = datas[-1]
    self.do_put(datas[0],filename)
   elif datas[1] == \'delete@#\':
    filename = datas[-1]
    self.delete(datas[0],filename)
 def run(self):
  # 创建套接字
  s = self.socket_tcp()
  while True:
   try:
    connfd,addr = s.accept()
   except KeyboardInterrupt:
    sys.exit(\"服务器退出\")
   except Exception as e:
    print(e)
    continue
   print(\"Connect from\",addr)
   # 创建子进程
   pid = os.fork()
   if pid == 0:
    s.close()
    self.do_request(connfd) #处理客户端具体请求
    os._exit(0)
   else:
    connfd.close()
if __name__ == \"__main__\":
 server = Server()
 server.run()
client.py
\"\"\"
 client.py
\"\"\"
import socket
import os,sys
import time
# 服务器地址
ADDR = (\"127.0.0.1\",8686)
FILE_PATH = \"./clientFiles/\"
# 客户端功能类
class Client(object):
 def __init__(self,account):
  self.sockfd = \"\"
  self.account = account
 #获得服务器文件列表
 def server_list(self):
  ftpServerFiles = []
  self.sockfd.send((self.account+\' LIST@# \').encode())
  # 等待回复
  data = self.sockfd.recv(128).decode()
  if data == \"OK\":
   files = self.sockfd.recv(4096).decode()
   for file in files.split(\'#\'):
    #print(file)
    ftpServerFiles.append(file)
  else:
   # 无法完成操作
   print(data)
  ftpServerFiles = ftpServerFiles[:-1]
  return ftpServerFiles
 #获得用户文件夹列表
 def client_list(self):
  # 获取文件列表
  userFiles = []
  file_list = os.listdir(FILE_PATH+self.account+\"/\")
  if not file_list:
   return
  else:
   time.sleep(0.1)
  files = \"\"
  for file in file_list:
   if file[0] != \'.\' and os.path.isfile(FILE_PATH + self.account + \"/\" + file):
    userFiles.append(file)
  return userFiles
 #退出
 def do_quit(self):
  self.sockfd.send((self.account+\' QUIT@# \').encode())
  self.sockfd.close()
  sys.exit(\'谢谢使用\')
 #用户下载服务器文件
 def do_get(self,filename):
  self.sockfd.send((self.account+\' GET@# \'+filename).encode())
  data = self.sockfd.recv(128).decode()
  if data == \'OK\':
   fd = open(FILE_PATH + self.account + \"/\" + filename,\'wb\')
   #复写
   while True:
    data = self.sockfd.recv(1024)
    if data == b\'##\':
     #print(\"##\")
     break
    #print(\"正在写入数据\")
    fd.write(data)
   fd.close()
  else:
   print(data)
 #用户将文件上传到服务器文件夹
 def do_put(self,filename):
  try:
   fd = open(FILE_PATH + self.account + \"/\" + filename,\'rb\')
  except IOError:
   print(\"文件不存在\")
   return
  # 获取文件名
  filename = filename.split(\'/\')[-1]
  # else:
  self.sockfd.send((self.account+\' PUT@# \'+filename).encode())
  data = self.sockfd.recv(128).decode()
  # 发送文件
  if data == \'OK\':
   while True:
    data = fd.read(1024)
    if not data:
     time.sleep(0.1)
     self.sockfd.send(b\'**\')
     break
    self.sockfd.send(data)
   fd.close()
   return \"true\"
  else:
   print(data)
   return \"false\"
 #删除用户文件
 def removeU(self,fileName):
  os.remove(FILE_PATH + self.account + \"/\" + fileName)
  return \"true\"
 #删除用户文件
 def removeF(self,fileName):
  self.sockfd.send((self.account+\' delete@# \'+fileName).encode())
  # 等待回复
  data = self.sockfd.recv(128).decode()
  if data == \"OK\":
   return \"true\"
 def menu_display(self):
  print(\"\\n------命令选择-------\")
  print(\"*** clist  ***\")
  print(\"*** slist  ***\")
  print(\"*** get list  ***\")
  print(\"*** put list  ***\")
  print(\"*** quit  ***\")
  print(\"----------------------\")
 def run(self,cmd):
  # 创建套接字
  sockfd = socket.socket()
  try:
   sockfd.connect(ADDR)
  except Exception as e:
   print(e)
   return
  result = \"\"
  self.sockfd = sockfd
  # choice(cmd,ftp)
  if cmd == \"slist\":
   result = self.server_list()
   return result
  elif cmd == \"clist\":
   result = self.client_list()
   return result
  elif cmd ==\'quit\':
   self.do_quit()
  elif cmd[:3] == \'get\':
   filename = cmd.strip().split(\' \')[-1]
   self.do_get(filename)
  elif cmd[:3] == \'put\':
   filename = cmd.strip().split(\' \')[-1]
   result = self.do_put(filename)
   return result
  elif cmd[:7] == \'removeU\':
   filename = cmd.strip().split(\' \')[-1]
   self.removeU(filename)
  elif cmd[:7] == \'removeF\':
   filename = cmd.strip().split(\' \')[-1]
   self.removeF(filename)
  else:
   print(\"请输入正确命令！\")
if __name__ == \"__main__\":
 client = Client(\"ffy\")
 client.run()

运行界面：