Question

我在网上搜索了很多但是还没有找到解决方案来通过套接字发送一个对象并按原样接收它。我知道它需要我已经做过的酸洗。并且将其转换为字节并且另一方面接收。但是如何将这些字节转换为该类型的对象。

        process_time_data = (current_process_start_time, current_process_end_time)
        prepared_process_data = self.prepare_data_to_send(process_time_data)
        data_string = io.StringIO(prepared_process_data)
        data_string =  pack('>I' ,len(data_string)) + data_string
        self.send_to_server(data_string)

这是将对象转换为客户端上的StringIO并发送到服务器的代码。在服务器端，我得到字节。现在我正在搜索要再次转换为StringIO的字节，以便我可以获取对象值。

在代码中，Object包装在StringIO中，并通过套接字发送。任何更好的方法将受到高度赞赏。

服务器端代码如下。

server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
#server.setblocking(0)
server.bind(('127.0.0.1',50000))
server.listen(5)
inputs = [server]
outputs = []
message_queues = {}

while inputs:
    readable, writeable, exceptional = select.select(inputs, outputs, inputs)
    for s in readable:
        if s is server:
            connection, client_address = s.accept()
            print(client_address)
            connection.setblocking(0)
            inputs.append(connection)
            message_queues[connection] = queue.Queue()
            print('server started...')
        else:
            print('Getting data step 1')
            raw_msglen = s.recv(4)
            msglen = unpack('>I',raw_msglen)[0]
            final_data = b''
            while len(final_data) < msglen:
                data = s.recv(msglen - len(final_data))
                if data:
                    #print(data)
                    final_data += data
                    message_queues[s].put(data)
                    if s not in outputs:
                        outputs.append(s)
                    else:
                        if s in outputs:
                            outputs.remove(s)
                else:
                    break
            inputs.remove(connection)
#            s.close()
            del message_queues[s]

            process_data = ProcessData()
            process_screen = ProcessScreen()

            if final_data is not None:
                try:
                    deserialized_data = final_data.decode("utf-8")
                    print(deserialized_data)
                except (EOFError):
                    break
            else:
                print('final data is empty.')

            print(process_data.project_id)
            print(process_data.start_time)
            print(process_data.end_time)
            print(process_data.process_id)

两个辅助函数如下

def receive_all(server, message_length, message_queues, inputs, outputs):
    # Helper function to recv message_length bytes or return None if EOF is hit
    data = b''
    while len(data) < message_length:
        packet = server.recv(message_length - len(data))
        if not packet:
            return None
        data += packet
        message_queues[server].put(data)
        if server not in outputs:
            outputs.append(server)
        else:
            if server in outputs:
                outputs.remove(server)
    inputs.remove(server)
    del message_queues[server]
    return data


def receive_message(server, message_queues, inputs, outputs):
    # Read message length and unpack it into an integer
    raw_msglen = receive_all(server, 4, message_queues, inputs, outputs)
    if not raw_msglen:
        return None
    message_length = unpack('>I', raw_msglen)[0]

    return receive_all(server, message_length, message_queues, inputs, outputs)

其中两个模型类如下

class ProcessData:
    process_id = 0
    project_id = 0
    task_id = 0
    start_time = 0
    end_time = 0
    user_id = 0
    weekend_id = 0

# Model class to send image data to the server
class ProcessScreen:
    process_id = 0
    image_data = bytearray()

Answer 1

您在这里寻找的是pickle以及loads和dumps操作。套接字基本上是字节流。让我们考虑你的情况。

class ProcessData:
    process_id = 0
    project_id = 0
    task_id = 0
    start_time = 0
    end_time = 0
    user_id = 0
    weekend_id = 0

需要通过执行data_string = pickle.dumps(ProcessData())将此类的实例腌制到数据字符串中，并通过执行data_variable = pickle.loads(data)进行取消操作，其中data是收到的内容。

因此，让我们考虑客户端创建ProcessData对象并将其发送到服务器的情况。这是客户端的样子。这是一个很小的例子。

客户端

import socket, pickle

class ProcessData:
    process_id = 0
    project_id = 0
    task_id = 0
    start_time = 0
    end_time = 0
    user_id = 0
    weekend_id = 0


HOST = 'localhost'
PORT = 50007
# Create a socket connection.
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))

# Create an instance of ProcessData() to send to server.
variable = ProcessData()
# Pickle the object and send it to the server
data_string = pickle.dumps(variable)
s.send(data_string)

s.close()
print 'Data Sent to Server'

现在接收此数据的服务器如下所示

服务器

import socket, pickle

class ProcessData:
    process_id = 0
    project_id = 0
    task_id = 0
    start_time = 0
    end_time = 0
    user_id = 0
    weekend_id = 0


HOST = 'localhost'
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr

data = conn.recv(4096)
data_variable = pickle.loads(data)
conn.close()
print data_variable
# Access the information by doing data_variable.process_id or data_variable.task_id etc..,
print 'Data received from client'

首先运行服务器在端口上创建bind，然后运行client通过套接字进行数据传输。您还可以查看this answer

Answer 2

Pickle对于网络通信不是特别安全，因为它可以用于注入可执行代码。我建议您改用json。

伪代码：

import json
to_send  = json.dumps(object)
s.sendall (to_send)

Answer 3

一个选项是使用 JSON 序列化。然而，Python 对象不可序列化，因此您必须首先使用函数 Dict（首选）或内置 vars 将类对象映射到 __dict__。

改编来自 Sudheesh Singanamalla 的答案并基于 this answer：

客户

import socket, json

class ProcessData:
    process_id = 0
    project_id = 0
    task_id = 0
    start_time = 0
    end_time = 0
    user_id = 0
    weekend_id = 0


HOST = 'localhost'
PORT = 50007
# Create a socket connection.
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))

# Create an instance of ProcessData() to send to server.
variable = ProcessData()

# Map your object into dict 
data_as_dict = vars(variable)

# Serialize your dict object
data_string = json.dumps(data_as_dict)

# Send this encoded object
s.send(data_string.encode(encoding="utf-8"))

s.close()
print 'Data Sent to Server'

服务器

import socket, json

class ProcessData:
    process_id = 0
    project_id = 0
    task_id = 0
    start_time = 0
    end_time = 0
    user_id = 0
    weekend_id = 0


HOST = 'localhost'
PORT = 50007
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr

data_encoded = conn.recv(4096)
data_string = data_encoded.decode(encoding="utf-8")

data_variable = json.loads(data_string)
# data_variable is a dict representing your sent object

conn.close()
print 'Data received from client'

警告

重要的一点是对象实例的字典映射不映射class variable，只映射instance variable。有关详细信息，请参阅此 anwser。示例：

class ProcessData:
    # class variables
    process_id = 0 
    project_id = 1

    def __init__(self):
        # instance variables
        self.task_id = 2
        self.start_time = 3

obj = ProcessData()
dict_obj = vars(obj)

print(dict_obj)
# outputs: {'task_id': 2, 'start_time': 3}

# To access class variables:
dict_class_variables = vars(ProcessData)

print(dict_class_variables['process_id'])
# outputs: 0

Python通过套接字发送和接收对象

3 个答案:

客户端

服务器

客户

服务器

警告