有我的域名就能直接访问,如何限制外来者ip访问
wsgi是协议
wsgi.ref是基于协议开发的一个模块
处理请求第一站:中间件(逻辑,全局性)
中间件
MIDDLEWARE = [ 'django.middleware.security.SecurityMiddleware', # 与安全相关 'django.contrib.sessions.middleware.SessionMiddleware', # 与session相关 'django.middleware.common.CommonMiddleware', 'django.middleware.csrf.CsrfViewMiddleware', # 与跨站请求相关 'django.contrib.auth.middleware.AuthenticationMiddleware', # 与用户认证系统相关 'django.contrib.messages.middleware.MessageMiddleware', # 与消息队列相关 'django.middleware.clickjacking.XFrameOptionsMiddleware', ]
中间件的方法
process_request
process_view
process_exception
process_response
关于带有下划线的方法
可以认为其不对外提供接口,只用于process_request,process_view,process_response调用
process_request,process_response
中间件被执行顺序
当用户发起请求的时候会依次经过所有的的中间件,这个时候的请求时process_request,最后到达views的函数中,views函数处理后,在依次穿过中间件,这个时候是process_response,最后返回给请求者。
如何自定义中间件
1、导入模块
from django.middleware.security import SecurityMiddleware # 与安全相关
2、注册模块
3、views
关于中间件的执行顺序
4、middleware
from django.utils.deprecation import MiddlewareMixin from django.shortcuts import HttpResponse class Md1(MiddlewareMixin): def process_request(self,request): print("Md1请求") def process_response(self,request,response): print("Md1返回") return response class Md2(MiddlewareMixin): def process_request(self,request): print("Md2请求") #return HttpResponse("Md2中断") def process_response(self,request,response): print("Md2返回") return response
结果:
Md1请求
Md2请求
view函数...
Md2返回
Md1返回
注意:如果当请求到达请求2的时候直接不符合条件返回,即return HttpResponse("Md2中断"),程序将把请求直接发给中间件2返回,然后依次返回到请求者,结果如下:
返回Md2中断的页面,后台打印如下:
Md1请求
Md2请求
Md2返回
Md1返回
流程
关于process_view
process_view(self, request, callback, callback_args, callback_kwargs)
middleware修改如下:
from django.utils.deprecation import MiddlewareMixin from django.shortcuts import HttpResponse class Md1(MiddlewareMixin): def process_request(self, request): print("Md1请求") # return HttpResponse("Md1中断") def process_response(self, request, response): print("Md1返回") return response def process_view(self, request, callback, callback_args, callback_kwargs): print("Md1 process_view") class Md2(MiddlewareMixin): def process_request(self, request): print("Md2请求") # return HttpResponse("Md2中断") def process_response(self, request, response): print("Md2返回") return response def process_view(self, request, callback, callback_args, callback_kwargs): print("Md2 process_view")
结果如下:
Md1请求
Md2请求
Md1 process_view
Md2 process_view
views index ...
Md2返回
Md1返回
如上,顺序为:当最后一个中间的process_request到达路由关系映射之后,返回到中间件1的process_view,然后依次往下,到达views函数,最后通过process_response依次返回到达用户。
process_view可以用来调用视图函数:
class Md1(MiddlewareMixin): def process_request(self,request): print("Md1请求") #return HttpResponse("Md1中断") def process_response(self,request,response): print("Md1返回") return response def process_view(self, request, callback, callback_args, callback_kwargs): # return HttpResponse("hello") response=callback(request,*callback_args,**callback_kwargs) return response
结果为:
Md1请求
Md2请求
view函数...
Md2返回
Md1返回
注意:process_view如果有返回值,会越过其他的process_view以及视图函数,但是所有的process_response都还会执行。
2、process_exception情况
自定义中间件:
class Md1(MiddlewareMixin): def process_request(self,request): print("Md1请求") #return HttpResponse("Md1中断") def process_response(self,request,response): print("Md1返回") return response def process_view(self, request, callback, callback_args, callback_kwargs): # return HttpResponse("hello") # response=callback(request,*callback_args,**callback_kwargs) # return response print("md1 process_view...") def process_exception(self): print("md1 process_exception...") class Md2(MiddlewareMixin): def process_request(self,request): print("Md2请求") # return HttpResponse("Md2中断") def process_response(self,request,response): print("Md2返回") return response def process_view(self, request, callback, callback_args, callback_kwargs): print("md2 process_view...") def process_exception(self): print("md1 process_exception...")
执行结果:
Md1请求
Md2请求
md1 process_view...
md2 process_view...
view函数...
Md2返回
Md1返回
由上可见,process_exception函数并没有没执行,为什么呢?因为此函数的是views函数执行出错时候,或者某一个中间件中此函数有返回值时才会被执行,但并不影响这四个函数的总体执行顺序,顺序分析如下: