一.什么是session
session是保存在服务端的键值对，Django默认支持Session，并且默认是将Session数据存储在数据库中，即：django_session 表中。
二.FVB中使用装饰器进行session验证
认证装饰器：
# 登陆验证
def auth(func):
'''判断是否登录装饰器'''
def inner(request, *args, **kwargs):
ck = request.session.get("username")
'''如果没有登陆返回到login.html'''
if not ck:
return redirect("/login.html")
return func(request, *args, **kwargs)
return inner
在需要认证的函数执行前加上装饰器认证即可，实际中应用如下：
def login(request):
if request.method == "GET":
return render(request, "login.html")
else:
username = request.POST.get("user")
pwd = request.POST.get("pwd")
pwd = md5(pwd)
dic = {"flag":False}
obj = User.objects.filter(username=username, pwd=pwd).first()
if obj:
request.session["username"] = username
return redirect("/index.html")
else:
print(dic)
return HttpResponse(json.dumps(dic))
@auth
def index(request):
user = request.session.get("username")
business = Business.objects.all().values("name")
host_list = Host.objects.all().values("id","host","port","business__name")
username = User.objects.all().values("username")
return render(request, 'index.html', {'host_list':host_list,"business":business,"user":user,"username":username})
@auth
def addhost(request):
business = Business.objects.all().values("name")
if request.method == "POST":
user = request.session.get("username")
host = request.POST.get("host")
port = request.POST.get("port")
select_business = request.POST.get("business")
business_id = Business.objects.filter(name=select_business).values("id")[0]
host = Host.objects.create(host=host,
port=port,
business_id=business_id["id"])
# host.business.add(*business)
return render(request, "index.html")
return render(request, "index.html", {"business":business})
@auth
def up_business(request):
if request.method == "POST":
user = request.session.get("username")
host= request.POST.get("host")
port= request.POST.get("port")
business_name = request.POST.get("business")
username = request.POST.get("username")
print(host,port,business_name,username)
return render(request,"保存成功")
三.CBV中使用类继承的方式进行session认证
- cbv是 class based view(基于类)
- cbv基于dispatch进行反射,get获取,post提交
- 应用场景：登录认证(继承dispatch,在dispatch里做session验证)
CBV第一种方式继承
1.单继承
扫盲：(继承的时候,一定要清楚self是哪个类实例化出来的对象,下例,self为B实例化的对象,任何属性优先从自己里面找,找不到在去父类里找)
class A(object):
def aaa(self):
print('from A')
def bbb(self):
self.aaa()
class B(A):
def aaa(self):
print('from B')
c = B()
c.aaa()
应用：
from django.views import View
class BaseView(View):
def dispatch(self, request, *args, **kwargs): # 继承父类的dispatch,因为父类里有返回值,所以也要有return
if request.session.get('username'):
response = super(BaseView, self).dispatch(request, *args, **kwargs)
return response
else:
return redirect('/login.html')
class IndexView(BaseView):
def get(self, request, *args, **kwargs):
return HttpResponse(request.session['username'])
2.多继承(继承顺序从左到右)
class BaseView(object):
def dispatch(self, request, *args, **kwargs):
if request.session.get('username'):
response = super(BaseView,self).dispatch(request, *args, **kwargs)
return response
else:
return redirect('/login.html')
class IndexView(BaseView,View):#先去找BaseView,BaseView中未定义在去找View
def get(self,request,*args,**kwargs):
return HttpResponse(request.session['username'])
CBV第二种方式装饰器
from django.utils.decorators import method_decorator
def auth(func): #定义装饰器
def inner(request,*args,**kwargs):
if request.session.get('username'):
obj = func(request,*args,**kwargs)
return obj
else:
return redirect('/login.html')
return inner
@method_decorator(auth,name='get') #放在类顶部就需要method_decorator这个装饰器
class IndexView(View):
@method_decorator(auth) #放在dispatch上就相当于全局都需要经过认证
def dispatch(self, request, *args, **kwargs):
if request.session.get('username'):
response = super(IndexView,self).dispatch(request, *args, **kwargs)
return response
else:
return redirect('/login.html')
@method_decorator(auth)
def get(self,request,*args,**kwargs):
return HttpResponse(request.session['username'])
@method_decorator(csrf_exempt) # 无效 csrf 放到post函数上的装饰器,是无效的,需要放到dispath上或者类上
def post(self,request,*args,**kwargs):
return HttpResponse(request.session['username'])
四.中间件middleware
如下是django的生命周期
如下为中间件的执行顺序
- 中间件执行时机：请求到来，请求返回时
- 中间件是一个类：
def process_request(self,request):
print('m2.process_request')
def process_response(self,request, response):
print('m2.prcess_response')
return response
- 应用：
- 请求日志
- 用户登录认证
Django根目录新建md文件夹，新建Middleware.py文件
from django.utils.deprecation import MiddlewareMixin
class M1(MiddlewareMixin):
'''先执行request,然后到url路由,url之后返回到最上方,在执行view,如果出现错误就直接到response上,执行完,到真正到视图,如果有问题就
执行exception,从下至上查找,如果找到exception就直接执行exception的return在走response返回用户
每个中间件中,4个方法不需要都写.
'''
def process_request(self,request):
if request.path_info == "/login.html":
return None
user_info = request.session.get("username")
if not user_info:
return redirect("/login.html")
注:新的django版本可能不存在MiddlewareMixin,需要手动写一下这个类进行继承
class MiddlewareMixin(object):
def __init__(self, get_response=None):
self.get_response = get_response
super(MiddlewareMixin, self).__init__()
def __call__(self, request):
response = None
if hasattr(self, 'process_request'):
response = self.process_request(request)
if not response:
response = self.get_response(request)
if hasattr(self, 'process_response'):
response = self.process_response(request, response)
return response
class M1(MiddlewareMixin):
def process_request(self,request):
if request.path_info == "/login.html":
return None
user_info = request.session.get("username")
if not user_info:
return redirect("/login.html")
settings里配置：
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',
'md.Middleware.M1',
]
WSGI_APPLICATION = 'BBS.wsgi.application'
SESSION_ENGINE = 'django.contrib.sessions.backends.db' # 引擎（默认）
SESSION_COOKIE_NAME = "sessionid" # Session的cookie保存在浏览器上时的key，即：sessionid＝随机字符串（默认）
SESSION_COOKIE_PATH = "/" # Session的cookie保存的路径（默认）
SESSION_COOKIE_DOMAIN = None # Session的cookie保存的域名（默认）
SESSION_COOKIE_SECURE = False # 是否Https传输cookie（默认）
SESSION_COOKIE_HTTPONLY = True # 是否Session的cookie只支持http传输（默认）
SESSION_COOKIE_AGE = 1209600 # Session的cookie失效日期（2周）（默认）
SESSION_EXPIRE_AT_BROWSER_CLOSE = False # 是否关闭浏览器使得Session过期（默认）
SESSION_SAVE_EVERY_REQUEST = True # 是否每次请求都保存Session，默认修改之后才保存（默认）