一、 Cookie和Session的发展史

• 一开始：只有一个页面，没有登录功能，大家看到东西都一样

  • 新闻

• 时代发展，出现了需要登录注册的网站，要有一门技术存储我们的登录信息

  • 京东、天猫

  • cookie

    • 存储形式：k:v键值对

    • 存储位置：客户端

    • 不安全，信息可能会泄露

• 时代发展，需要有一门新的安全的技术

  • session

  • 标识符，来表示我是当前用户加密出来的数据

  • 对敏感信息进行加密处理

    • 存储服务端：

    • 标识符配合上你的加密串

  • 把我的标识符+ 字符串全给客户端

    • 客户端存储格式

      • session_id:返回回来的表示符+加密串

• token

  • 三段式加密

 二、Cookie

2.1 设置cookie

HttpResponse
render
redriect

obj = HttpResponse("ok")
obj.set_cookie('k','v')

def login(request, *args, **kwargs):if request.method == 'POST':username = request.POST.get("username")password = request.POST.get("password")if username == "dream" and password == "521":obj = HttpResponse("ok")obj.set_cookie('sign', 'user')return objelse:return redirect('/login/')return render(request, 'login.html')

2.2 取值

cookie取值验证：

def home(request, *args, **kwargs):sign = request.COOKIES.get('sign')if sign and sign == 'user':return HttpResponse("这是home页面")else:return redirect('/login/')

 完整版 cookie登录注册：

def login(request, *args, **kwargs):# next_url = request.get_full_path()# print(next_url) # /login/?next_url=/home/if request.method == 'POST':username = request.POST.get("username")password = request.POST.get("password")if username == "dream" and password == "521":next_url = request.GET.get('next_url')# print(next_url) # /home/obj = redirect(next_url)obj.set_cookie('sign', 'user')return objelse:return redirect('/login/')return render(request, 'login.html')def login_auth(func):def inner(request, *args, **kwargs):# print(request.path_info) #  /home/# print(request.get_full_path()) # /home/?username=111next_url = request.get_full_path()  # /home/# print(next_url)# /home/sign = request.COOKIES.get('sign')if sign and sign == 'user':res = func(request, *args, **kwargs)return reselse:return redirect(f'/login/?next_url={next_url}')return inner@login_auth
def home(request, *args, **kwargs):return HttpResponse("这是home页面")# def home(request, *args, **kwargs):
#     sign = request.COOKIES.get('sign')
#     if sign and sign == 'user':
#         return HttpResponse("这是home页面")
#     else:
#         return redirect('/login/')@login_auth
def index(request, *args, **kwargs):return HttpResponse("这是index页面")

2.3  设置过期时间

obj.set_cookie('sign', 'user', expires=3)
obj.set_cookie('sign', 'user', max_age=3)

2.4  刪除cookie

def logout(request, *args, **kwargs):obj = redirect('/home/')# 设置超时时间 5s 到期obj.delete_cookie('sign')return obj

三、  Session

3.1 设置session

request.session['sign'] = 'user'

3.2  取值session

sign = request.session.get('sign')

def login(request, *args, **kwargs):# next_url = request.get_full_path()# print(next_url) # /login/?next_url=/home/if request.method == 'POST':username = request.POST.get("username")password = request.POST.get("password")if username == "dream" and password == "521":# next_url = request.GET.get('next_url')# print(next_url) # /home/request.session['sign'] = 'user'obj = redirect('/home/')# 设置过期时间# obj.set_cookie('sign', 'user', expires=3)# obj.set_cookie('sign', 'user', max_age=3)return objelse:return redirect('/login/')return render(request, 'login.html')def login_auth(func):def inner(request, *args, **kwargs):# print(request.path_info) #  /home/# print(request.get_full_path()) # /home/?username=111next_url = request.get_full_path()  # /home/# print(next_url)# /home/sign = request.session.get('sign')# print(sign) # userif sign and sign == 'user':res = func(request, *args, **kwargs)return reselse:return redirect(f'/login/?next_url={next_url}')return inner@login_auth
def home(request, *args, **kwargs):return HttpResponse("这是home页面")

注： 

• session基于数据库表才能使用的

  • 必须先迁移数据库，生成 django_session 表

• session只对当次登录有效

  • 主动清除浏览器中本地存在的session

  • 验签发现，没有sessionid就会自动生成新的session

• django_sessoin表中的数据条数取决于浏览器

• 同一个计算机(IP地址)上同一个浏览器只会有一条数据生效

• 同一个计算机(IP地址)上多个浏览器会有多个数据生效

• 当session过期的时候，可能会出现多条数据对应一个浏览器

  • 但是这些数据不会持久化存储，会被定时清理掉，可以手动清除也可以代码清除

• 目的是为了节省服务器数据库资源

3.3  session设置过期时间

request.session['sign'] = 'user'# 如果是数字的话就是指定 s shu# request.session.set_expiry(3)# 0 就是关闭浏览器后自动清除浏览器的sessionidrequest.session.set_expiry(0)

3.4  删除session

 # 删除session方式一# request.session.delete()# 把浏览器和数据库里面的session全部清除掉request.session.flush()

四、  CBV加装饰器的三种方法

 4.1 方式一：加载视图函数上面

 @method_decorator(login_auth)def get(self, request, *args, **kwargs):return HttpResponse("这是home页面")def post(self):...

4.2   方式二：放在类视图上面 (放的装饰器函数,name指定你的视图函数里面的方法)

@method_decorator(login_auth, name='get')
@method_decorator(login_auth, name='post')
class UserView(View):

4.3   方式三 ： dispactch 方法加装饰器 ： 本视图函数内所有的视图都需要走装饰器

@method_decorator(login_auth)def dispatch(self, request, *args, **kwargs):# Try to dispatch to the right method; if a method doesn't exist,# defer to the error handler. Also defer to the error handler if the# request method isn't on the approved list.if request.method.lower() in self.http_method_names:handler = getattr(self, request.method.lower(), self.http_method_not_allowed)else:handler = self.http_method_not_allowedreturn handler(request, *args, **kwargs)