网上很多写法，都是传统的写法，
process_request和process_response方法，还可以用，但process_view的执行流程已经不行了。
看了官方文档，推荐的写法，也是用__call__方法来作实现了。
我试了新老方法，从输出，可以看出效果了。
中间件处理的顺序还是request从上到下，response从下回到上的。
from django.utils.deprecation import MiddlewareMixin
from django.shortcuts import HttpResponse
class Row1(MiddlewareMixin):
def __init__(self, get_response):
self.get_response = get_response
# One-time configuration and initialization.
def process_request(self, request):
print('中间件1的请求')
def process_response(self, request, response):
print('中间件1的返回')
return response
def __call__(self, request):
# Code to be executed for each request before
# the view (and later middleware) are called.
print('中间件1的 view前调用')
response = self.get_response(request)
# Code to be executed for each request before
# the view (and later middleware) are called.
print('中间件1的 view之后调用')
return response
class Row2(MiddlewareMixin):
def __init__(self, get_response):
self.get_response = get_response
# One-time configuration and initialization.
def process_request(self, request):
print('中间件2的请求')
# return HttpResponse('前端显示：中间件：M2.process_request')
def process_response(self, request, response):
print('中间件2的返回')
return response
def __call__(self, request):
# Code to be executed for each request before
# the view (and later middleware) are called.
print('中间件2的 view前调用')
response = self.get_response(request)
# Code to be executed for each request before
# the view (and later middleware) are called.
print('中间件2的 view之后调用')
return response
class Row3(MiddlewareMixin):
def __init__(self, get_response):
self.get_response = get_response
# One-time configuration and initialization.
def process_request(self, request):
print('中间件3的请求')
def process_response(self, request, response):
print('中间件3的返回')
return response
def process_view(self, request, callback, callback_args, callback_kwargs):
print('中间件3的 view')
settings.py里的排列：
MIDDLEWARE = [
'django.middleware.security.SecurityMiddleware',
'django.contrib.sessions.middleware.SessionMiddleware',
'django.middleware.common.CommonMiddleware',
'django.middleware.csrf.CsrfViewMiddleware',
'django.contrib.auth.middleware.AuthenticationMiddleware',
'django.contrib.messages.middleware.MessageMiddleware',
'django.middleware.clickjacking.XFrameOptionsMiddleware',
'Middle.cm1.Row1',
'Middle.cm1.Row2',
'Middle.cm1.Row3',
]
输出，注意Row3里process_view输出没有反应，
而Row1和Row2的process_request, process_rewponse的输出被忽略。
Quit the server with CTRL-BREAK. 中间件1的 view前调用 中间件2的 view前调用 中间件3的请求 中间件3的返回 中间件2的 view之后调用 中间件1的 view之后调用 [03/Jan/2019 20:08:58] "GET / HTTP/1.1" 200 16348