通过套接字发送包含文件的字典(python)
是否可以通过套接字将包含文件(图像或文档)的dict作为值发送 我试过像贝娄这样的方法,但失败了通过套接字发送包含文件的字典(python),python,file,sockets,dictionary,send,Python,File,Sockets,Dictionary,Send,是否可以通过套接字将包含文件(图像或文档)的dict作为值发送 我试过像贝娄这样的方法,但失败了 with open("cat.jpeg", "rb") as f: myFile = f.read(2048) data = {"id": "1283", "filename": "cat.jpeg", "file": myFile} dataToSend = json.dumps(data).encode("utf-8") 这会导致json错误,myFile是无法序列化的字节数组 我
with open("cat.jpeg", "rb") as f:
myFile = f.read(2048)
data = {"id": "1283", "filename": "cat.jpeg", "file": myFile}
dataToSend = json.dumps(data).encode("utf-8")
这会导致json错误,myFile是无法序列化的字节数组
我尝试使用base64编码将myFile转换为字符串,但没有成功
部分起作用的是将myFile转换成字符串,比如str(myFile)。json序列化程序工作正常,我通过套接字发送,dict正常,但myFile数据已损坏,因此我无法重新创建图片
那么,是否可以使用这种方法,或者如何通过套接字发送文件和数据,以便在另一端轻松解析
乐:
使用base64编码仍然不起作用,myFile仍然是“字节”格式和
json给出了以下错误:“字节”类型的对象不可json序列化
客户
import os
import base64
import json
import socket
currentPath = os.path.dirname(os.path.abspath(__file__)) + "\\downloads\\"
with open(currentPath + "cat.png", "rb") as f:
l = f.read()
print(type(l)) #prints <class 'bytes'>
myFile = base64.b64encode(l)
print(type(myFile)) #prints <class 'bytes'>
data = {"id": "12", "filename": "cat.png", "message": "So cute!", "file": myFile}
dataToSend = json.dumps(data).encode("utf-8") #prints TypeError: Object of type 'bytes' is not JSON serializable
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("127.0.0.1", 1234))
s.sendall(dataToSend)
s.close()
您应该能够做到:
data = base64.b64encode(myFile)
dataToSend = json.dumps({"id":"1283","filename":"cat.jpeg", "file":data})
然后通过套接字发送。当您在套接字的另一端接收数据时,只需执行以下操作:
jsonDict = json.loads(dataReceived)
data = base64.b64decode(jsonDict["file"])
更好的方法可能是只使用bson
您应该能够做到:
data = base64.b64encode(myFile)
dataToSend = json.dumps({"id":"1283","filename":"cat.jpeg", "file":data})
然后通过套接字发送。当您在套接字的另一端接收数据时,只需执行以下操作:
jsonDict = json.loads(dataReceived)
data = base64.b64decode(jsonDict["file"])
更好的方法可能是只使用bson
正如我在评论中所说的,将二进制数据打包成字符串格式(如JSON)是一种浪费——如果使用base64,则会将数据传输大小增加33%,这也使得JSON解码器很难正确解码JSON,因为它需要通过整个结构来提取索引 最好分别发送它们——JSON作为JSON,然后文件内容直接作为二进制。当然,您需要一种区分两者的方法,最简单的方法是在发送JSON数据时只在JSON数据前面加上其长度,以便服务器知道要读取多少字节才能获得JSON,然后读取其余的字节作为文件内容。这将使其成为一种非常简单的协议,包的形式如下:
[JSON LENGTH][JSON][FILE CONTENTS]
假设JSON永远不会超过4GB(如果是的话,你会遇到更大的问题,因为解析它将是一场噩梦),将固定4字节(32位)的JSON长度作为无符号整数就足够了(如果你不希望JSON超过64KB,你甚至可以选择16位)因此,整个策略将在客户端起作用,如下所示:
创建有效负载
将其编码为JSON,然后使用UTF-8编码将其编码为bytes
获取上述包的长度,并将其作为流的前4个字节发送
发送JSON包
读取并发送文件内容
在服务器端,您执行相同的过程
读取接收数据的前4个字节以获取JSON有效负载长度
读取下一个字节数以匹配此长度
使用UTF-8将它们解码为字符串,然后解码JSON以获得有效负载
读取其余的流数据并将其存储到文件中
或在代码中,客户端:
import json
import os
import socket
import struct
BUFFER_SIZE = 4096 # a uniform buffer size to use for our transfers
# pick up an absolute path from the script folder, not necessary tho
file_path = os.path.abspath(os.path.join(os.path.dirname(__file__), "downloads", "cat.png"))
# let's first prepare the payload to send over
payload = {"id": 12, "filename": os.path.basename(file_path), "message": "So cute!"}
# now JSON encode it and then turn it onto a bytes stream by encoding it as UTF-8
json_data = json.dumps(payload).encode("utf-8")
# then connect to the server and send everything
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s: # create a socket
print("Connecting...")
s.connect(("127.0.0.1", 1234)) # connect to the server
# first send the JSON payload length
print("Sending `{filename}` with a message: {message}.".format(**payload))
s.sendall(struct.pack(">I", len(json_data))) # pack as BE 32-bit unsigned int
# now send the JSON payload itself
s.sendall(json_data) # let Python deal with the buffer on its own for the JSON...
# finally, open the file and 'stream' it to the socket
with open(file_path, "rb") as f:
chunk = f.read(BUFFER_SIZE)
while chunk:
s.send(chunk)
chunk = f.read(BUFFER_SIZE)
# alternatively, if you're using Python 3.5+ you can just use socket.sendfile() instead
print("Sent.")
和服务器:
import json
import os
import socket
import struct
BUFFER_SIZE = 4096 # a uniform buffer size to use for our transfers
target_path = os.path.abspath(os.path.join(os.path.dirname(__file__), "fileCache"))
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind(("127.0.0.1", 1234)) # bind to the 1234 port on localhost
s.listen(0) # allow only one connection so we don't have to deal with data separation
while True:
print("Waiting for a connection...")
connection, address = s.accept() # wait for and accept the incoming connection
print("Connection from `{}` accepted.".format(address))
# read the starting 32 bits and unpack them into an int to get the JSON length
json_length = struct.unpack(">I", connection.recv(4))[0]
# now read the JSON data of the given size and JSON decode it
json_data = b"" # initiate an empty bytes structure
while len(json_data) < json_length:
chunk = connection.recv(min(BUFFER_SIZE, json_length - len(json_data)))
if not chunk: # no data, possibly broken connection/bad protocol
break # just exit for now, you should deal with this case in production
json_data += chunk
payload = json.loads(json_data.decode("utf-8")) # JSON decode the payload
# now read the rest and store it into a file at the target path
file_path = os.path.join(target_path, payload["filename"])
with open(file_path, "wb") as f: # open the target file for writing...
chunk = connection.recv(BUFFER_SIZE) # and stream the socket data to it...
while chunk:
f.write(chunk)
chunk = connection.recv(BUFFER_SIZE)
# finally, lets print out that we received the data
print("Received `{filename}` with a message: {message}".format(**payload))
导入json
导入操作系统
导入套接字
导入结构
缓冲区大小=4096#用于传输的统一缓冲区大小
target\u path=os.path.abspath(os.path.join(os.path.dirname(\uuu file\uuu),“fileCache”))
将socket.socket(socket.AF_INET,socket.SOCK_STREAM)作为s:
s、 绑定(((“127.0.0.1”,1234))#绑定到本地主机上的1234端口
s、 侦听(0)#只允许一个连接,因此我们不必处理数据分离问题
尽管如此:
打印(“正在等待连接…”)
连接,地址=s.accept()#等待并接受传入连接
打印(“已接受来自`{}`的连接。”。格式(地址))
#读取起始的32位,并将其解压为int以获得JSON长度
json_length=struct.unpack(“>I”,connection.recv(4))[0]
#现在读取给定大小的JSON数据并对其进行JSON解码
json_data=b“”#启动一个空字节结构
而len(json_数据)
注意:请记住,这是Python3.x代码-对于Python2.x,您必须自己处理上下文管理,而不是使用with…
块来打开/关闭套接字
这就是全部。当然,在实际环境中,您需要处理断开连接、多个客户端等问题,但这是基本过程。正如我在评论中所说,将二进制数据打包为字符串格式(如JSON)这是浪费—如果使用base64,则会将数据传输大小增加33%,这也会使JSON解码器很难正确解码JSON,因为它需要流式传输整个结构以提取索引
最好分别发送它们——JSON作为JSON,然后文件内容直接作为二进制。当然,您需要一种区分两者的方法,最简单的方法就是在JSON数据前面加上它的l
base64_bytes = b64encode(l)
myFile = base64_bytes.decode("utf-8")
import os
from base64 import b64encode
import json
import socket
currentPath = os.path.dirname(os.path.abspath(__file__)) + "\\downloads\\"
with open(currentPath + "cat.png", "rb") as f:
l = f.read()
base64_bytes = b64encode(l)
myFile = base64_bytes.decode("utf-8")
data = {"id": "12", "filename": "cat.png", "message": "So cute!", "file": myFile}
dataToSend = json.dumps(data).encode("utf-8")
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(("127.0.0.1", 1234))
s.sendall(dataToSend)
s.close()
import socket
import json
import os
import sys
import base64
currentPath = os.path.dirname(os.path.abspath(__file__)) + "\\fileCache\\"
tempData = bytearray()
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(("127.0.0.1", 1234))
s.listen(5)
conn, addr = s.accept()
while True:
dataReceived = conn.recv(4096)
if sys.getsizeof(dataReceived) > 17:
tempData = tempData + dataReceived
else:
data = json.loads(tempData.decode("utf-8"))
break
myFile = base64.b64decode(data["file"])
with open(currentPath + data["filename"], "wb") as f:
f.write(myFile)
f.close()