Cookies and session keeping technology

conversation ： The browser visits the website until the end of the visit is a session
HTTP Protocol is stateless .cookies and session Two storage technologies to solve the stateless problem .

1.cookies

Is the storage space saved on the client browser
Store in the form of key value pairs on the browser , Stored data has a lifecycle , Secure domain storage isolation , Cannot access between different domains . At every request , The browser will carry cookies To the server .

1.1 cookies Use

HttpResponse.set_cookie(key,value='',max_age=None,expires=None)

• key cookie Name
• value cookie Value
• max_age Survival time , second
• expires Specific expiration time
• When not formulated max_age perhaps expires when , When the browser is closed, it will fail

#  Set up cookies
def set_cookies(request):
    resp = HttpResponse('set cookies is ok')
    resp.set_cookie('uuname','nicos',500)
    return resp
#  obtain cookies
def get_cookies(request):
    resp = request.COOKIES.get('uuname','null')
    return HttpResponse('cookie is :%s'%(resp))
#  Delete cookies
def del_cookies(request):
    resp = HttpResponse(' Delete COOKIES')
    resp.delete_cookie('uuname')
    return resp

2. session

The space on the server is used to store important data of browser server interaction , Use session You must first enable cookie, And cookie Storage in sessionid, Each client can have an independent session, Requestors are independent .sessionid Because saved in cookies, So the life cycle is the same as him
Use sessionn, Check settings.py Whether to add
INSTALLED_APPS = [
’django.contrib.sessions’,
MIDDLEWARE = [
’django.contrib.sessions.middleware.SessionMiddleware’,

def set_session(request):
    request.session['uuname']='wwwwww'
    return HttpResponse('set session is ok')

def get_session(request):
    value = request.session['uuname']
    return HttpResponse(value)

settings.py Related configuration items in
1.session_cookie_age: Appoint sessionid stay cookies Length of time saved in , The default is 2 Zhou .
2.session_expire_at_borwser_close=True If you close the browser, it won't work
3.Django Medium session Data stored in database , So use session sign , Need to ensure that migrate.
4.session It is a continuous single table involving , And change the data for two continuous holdings
5. Can be performed every night python manage.py clearsessions, This command deletes expired session data .