ContentType

application/x-www-form-urlencoded

form数据被编码为名称/值对。这是标准的编码格式。

即: form数据会被encode成键值对id=123&name='xiaoming' , 与url通过?拼接.
转义:

• 空格转义为+ ;
• 保留字符转移参见RFC1738的第2.2节;
• 非字母数字字符替换为%HH, 即对应的ascii的十六进制形式;
• 换行字符CRLF 转义为 %0D%0A

• 名称与值通过=连接, 名称值对之间使用&连接.

  
  
  图片.png

参见: https://www.w3.org/TR/html401/interact/forms.html#h-17.13.4

对于python3 , 使用urllib3时, 需要使用 from urllib.parse import urlencode , encoded_args = urlencode(startfields)

application/json

使用json的特点是, post的数据可以有层级嵌套结构 .
后台需要使用 @RequestBody 注解来获取.
前端发送时, 像urllib3 , 需要进行json编码然后放到body中,

>>> import json
>>> data = {'attribute': 'value'}
>>> encoded_data = json.dumps(data).encode('utf-8')
>>> r = http.request(
...     'POST',
...     'http://httpbin.org/post',
...     body=encoded_data,
...     headers={'Content-Type': 'application/json'})
>>> json.loads(r.data.decode('utf-8'))['json']
{'attribute': 'value'}

multipart/form-data

用来上传包含文件, non-ascii数据和二进制数据的表单.
在表单中使用Content-Dispositon 来进行分割表单的各个部分 :

The following example illustrates "multipart/form-data" encoding. Suppose we have the following form:

 

   

   What is your name? 

   What files are you sending? 

    
 
If the user enters "Larry" in the text input, and selects the text file "file1.txt", the user agent might send back the following data:

   Content-Type: multipart/form-data; boundary=AaB03x

   --AaB03x
   Content-Disposition: form-data; name="submit-name"

   Larry
   --AaB03x
   Content-Disposition: form-data; name="files"; filename="file1.txt"
   Content-Type: text/plain

   ... contents of file1.txt ...
   --AaB03x--
If the user selected a second (image) file "file2.gif", the user agent might construct the parts as follows:

   Content-Type: multipart/form-data; boundary=AaB03x

   --AaB03x
   Content-Disposition: form-data; name="submit-name"

   Larry
   --AaB03x
   Content-Disposition: form-data; name="files"
   Content-Type: multipart/mixed; boundary=BbC04y

   --BbC04y
   Content-Disposition: file; filename="file1.txt"
   Content-Type: text/plain

   ... contents of file1.txt ...
   --BbC04y
   Content-Disposition: file; filename="file2.gif"
   Content-Type: image/gif
   Content-Transfer-Encoding: binary

   ...contents of file2.gif...
   --BbC04y--
   --AaB03x--