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cookies与session

一、cookies

  • 本质:浏览器端保存的键值对

  • 方便客户按照自己的习惯操作页面或软件,例如:用户验证,登陆界面,右侧菜单隐藏,控制页面列表显示条数...

  • cookies是由服务端写在浏览器端,以后每次请求的时候,浏览器都携带者cookie来访问

 

  cookie的设置方式

  • tronado(后台设置)

  1. self.cookies
  2. self.get_cookie("k1")
  3. self.set_cookie("k2","v2")
  • 前端js设置

  1. document.cookie
  2. document.cookie.split(“;”)  获取所有的cookie列表
  3. document.cookie = “k3=66” 设置
  4. document.cookie = “k3=66;path=‘/”

 

  基本操作

后台设置

import tornado.ioloopimport tornado.webclass MainHandler(tornado.web.RequestHandler):    def get(self, *args, **kwargs):        print(self.cookies)        print(self.get_cookie(‘k1‘))        self.set_cookie(‘k2‘, ‘999‘)        self.render(‘index.html‘)settings = {    ‘template_path‘:‘views‘,}application = tornado.web.Application([    (r"/index", MainHandler),],**settings)if __name__ == "__main__":    application.listen(8888)    tornado.ioloop.IOLoop.instance().start()

 

前端设置

<!DOCTYPE html><html lang="en"><head>    <meta charset="UTF-8">    <title>Title</title></head><body> <script>    function setCookieBySeconds(name, value, expires) {        var current_date = new Date();        current_date.setDate(current_date.getSeconds()+expires);        document.cookie = name + ‘= ‘ + value +‘;expires=‘ + current_date.toUTCString();    }      function setCookieByDays(name, value, expires) {        var current_date = new Date();        current_date.setDate(current_date.getDate()+expires);        document.cookie = name + ‘= ‘ + value +‘;expires=‘ + current_date.toUTCString();    }     //此外还可以导入jquery.cookie.js后通过    // $.cookie(‘k1‘,‘v1‘,{expires:7});设置过期时间为7天</script></body></html>

 

  加密cookie(签名)

  cookie很容易被恶意的客户端伪造,加入你想在cookie中保存当前登陆用户的id之类的信息,你需要对cookie做签名以防止伪造,Tornado通过set_secure_cookie和get_secure_cookie方法直接支持了这种功能,要使用这些方法,你需要在创建应用一个密钥,名字为cookie_secret(在settings配置cookie_secret)

  签名Cookie的本质是:

写cookie过程:

  • 将值进行base64加密
  • 对除值以外的内容进行签名,哈希算法(无法逆向解析)
  • 拼接 签名 + 加密值

读cookie过程:

  • 读取 签名 + 加密值
  • 对签名进行验证
  • base64解密,获取值内容
import tornado.ioloopimport tornado.web  class MainHandler(tornado.web.RequestHandler):     def get(self):        login_user = self.get_secure_cookie("login_user", None)        if login_user:            self.write(login_user)        else:            self.redirect(‘/login‘)  class LoginHandler(tornado.web.RequestHandler):    def get(self):        self.current_user()         self.render(‘login.html‘, **{‘status‘: ‘‘})     def post(self, *args, **kwargs):         username = self.get_argument(‘name‘)        password = self.get_argument(‘pwd‘)        if username == ‘wupeiqi‘ and password == ‘123‘:            self.set_secure_cookie(‘login_user‘, ‘武沛齐‘)            self.redirect(‘/‘)        else:            self.render(‘login.html‘, **{‘status‘: ‘用户名或密码错误‘}) settings = {    ‘template_path‘: ‘template‘,    ‘static_path‘: ‘static‘,    ‘static_url_prefix‘: ‘/static/‘,    ‘cookie_secret‘: ‘aiuasdhflashjdfoiuashdfiuh‘} application = tornado.web.Application([    (r"/index", MainHandler),    (r"/login", LoginHandler),], **settings)  if __name__ == "__main__":    application.listen(8888)    tornado.ioloop.IOLoop.instance().start()

 

二、session

  • cookie保存单一键值对,session保存多个键值对

  • cookie是保存在客户端上,session是保存在服务端

  • session是基于cookie人为构建的

  • session在服务端存储类似于字典样式的结构,可以存在全局变量,数据库,文件,memcached radis,但是不能放在局部变量里

技术分享

 

  1、面向对象基础

  • 面向对象中通过索引的方式访问对象,需要内部实现__getitem__、__delitem__、__setitem__方法

class Foo(object):    def __getitem__(self, key):        print(‘__getitem__‘,key)    def __setitem__(self, key, value):        print(‘__setitem__‘,key,value)    def __delitem__(self, key):        print(‘__delitem__‘,key) obj = Foo()result = obj[‘k1‘]#obj[‘k2‘] = ‘wupeiqi‘#del obj[‘k1‘]

 

  2、Tornado扩展

  • Tornado框架中,默认执行Handler的get/post等方法之前默认会执行initialize方法,所以可以通过自定义的方式使得所有请求在处理前执行操作..
class BaseHandler(tornado.web.RequestHandler):       def initialize(self):        self.xxoo = "wupeiqi"      class MainHandler(BaseHandler):       def get(self):        print(self.xxoo)        self.write(‘index‘) class IndexHandler(BaseHandler):       def get(self):        print(self.xxoo)        self.write(‘index‘)

 

  3、自定义session

import tornado.ioloopimport tornado.webfrom hashlib import sha1import os, time#将session以全局变量的形式保存session_container = {}#创建cookie_str随机字符串  的函数create_session_id = lambda: sha1(‘%s%s‘ % (os.urandom(16), time.time())).hexdigest()class Session(object):    #静态字段--session key名    session_id = "__sessionId__"    def __init__(self, request):        #尝试获取__sessionId__        session_value = http://www.mamicode.com/request.get_cookie(Session.session_id)"__sessionId__:随机字符串"        request.set_cookie(Session.session_id, self._id)    def __getitem__(self, key):        return session_container[self._id][key]    def __setitem__(self, key, value):        if session_container.has_key(self._id):            session_container[self._id][key] = value        else:            session_container[self._id] = {key: value}    def __delitem__(self, key):        del session_container[self._id][key]class BaseHandler(tornado.web.RequestHandler):    def initialize(self):        # my_session[‘k1‘]访问 __getitem__ 方法        #实例session对象,实现索引访问        self.my_session = Session(self)class MainHandler(BaseHandler):    def get(self):        print(self.my_session[‘c_user‘])        print(self.my_session[‘c_card‘])        self.write(‘index‘)class LoginHandler(BaseHandler):    def get(self):        self.render(‘login.html‘, **{‘status‘: ‘‘})    def post(self, *args, **kwargs):        username = self.get_argument(‘name‘)        password = self.get_argument(‘pwd‘)        if username == ‘wupeiqi‘ and password == ‘123‘:            self.my_session[‘c_user‘] = ‘wupeiqi‘            self.my_session[‘c_card‘] = ‘12312312309823012‘            self.redirect(‘/index‘)        else:            self.render(‘login.html‘, **{‘status‘: ‘用户名或密码错误‘})settings = {    ‘template_path‘: ‘views‘,    ‘static_path‘: ‘static‘,    ‘static_url_prefix‘: ‘/static/‘,    ‘cookie_secret‘: ‘aiuasdhflashjdfoiuashdfiuh‘,    ‘login_url‘: ‘/login‘}application = tornado.web.Application([    (r"/index", MainHandler),    (r"/login", LoginHandler),], **settings)if __name__ == "__main__":    application.listen(8888)    tornado.ioloop.IOLoop.instance().start()

 

cookies与session