前言
Cookie和Session相信对大家来说并不陌生,简单来说,Cookie和Session都是为了记录用户相关信息的方式,最大的区别就是Cookie在客户端记录而Session在服务端记录内容。
那么Cookie和Session之间的联系是怎么建立的呢?换言之,当服务器接收到一个请求时候,根据什么来判断读取哪个Session的呢?
对于Django默认情况来说,当用户登录后就可以发现Cookie里有一个sessionid的字段,根据这个key就可以取得在服务器端记录的详细内容。如果将这个字段删除,刷新页面就会发现变成未登录状态了。
对于Session的处理主要在源码django/contrib/sessions/middleware.py中,如下所示:
import time from importlib import import_module from django.conf import settings from django.contrib.sessions.backends.base import UpdateError from django.core.exceptions import SuspiciousOperation from django.utils.cache import patch_vary_headers from django.utils.deprecation import MiddlewareMixin from django.utils.http import cookie_date class SessionMiddleware(MiddlewareMixin): def __init__(self, get_response=None): self.get_response = get_response engine = import_module(settings.SESSION_ENGINE) self.SessionStore = engine.SessionStore def process_request(self, request): session_key = request.COOKIES.get(settings.SESSION_COOKIE_NAME) request.session = self.SessionStore(session_key) def process_response(self, request, response): """ If request.session was modified, or if the configuration is to save the session every time, save the changes and set a session cookie or delete the session cookie if the session has been emptied. """ try: accessed = request.session.accessed modified = request.session.modified empty = request.session.is_empty() except AttributeError: pass else: # First check if we need to delete this cookie. # The session should be deleted only if the session is entirely empty if settings.SESSION_COOKIE_NAME in request.COOKIES and empty: response.delete_cookie( settings.SESSION_COOKIE_NAME, path=settings.SESSION_COOKIE_PATH, domain=settings.SESSION_COOKIE_DOMAIN, ) else: if accessed: patch_vary_headers(response, ('Cookie',)) if (modified or settings.SESSION_SAVE_EVERY_REQUEST) and not empty: if request.session.get_expire_at_browser_close(): max_age = None expires = None else: max_age = request.session.get_expiry_age() expires_time = time.time() + max_age expires = cookie_date(expires_time) # Save the session data and refresh the client cookie. # Skip session save for 500 responses, refs #3881. if response.status_code != 500: try: request.session.save() except UpdateError: raise SuspiciousOperation( "The request's session was deleted before the " "request completed. The user may have logged " "out in a concurrent request, for example." ) response.set_cookie( settings.SESSION_COOKIE_NAME, request.session.session_key, max_age=max_age, expires=expires, domain=settings.SESSION_COOKIE_DOMAIN, path=settings.SESSION_COOKIE_PATH, secure=settings.SESSION_COOKIE_SECURE or None, httponly=settings.SESSION_COOKIE_HTTPONLY or None, ) return response
当接收到一个请求时候,先在Cookie里取出key,然后根据key创建Session对象,在response时候判断是否要删除或者修改sessionid。
也就是说,Django中如果客户把浏览器Cookie禁用后,用户相关的功能就全都失效了,因为服务端根本没法知道当前用户是谁。
对于这种情况,关键点就是如何把sessionid不使用Cookie传递给客户端,常见的比如放在URL中,也就是URL重写技术。想实现这点可以自己写Middleware。不过django并不建议这么做:
The Django sessions framework is entirely, and solely, cookie-based. It does not fall back to putting session IDs in URLs as a last resort, as PHP does. This is an intentional design decision. Not only does that behavior make URLs ugly, it makes your site vulnerable to session-ID theft via the “Referer” header.
总结
以上就是这篇文章的全部内容了,希望本文的内容对大家的学习或者工作能带来一定的帮助,如果有疑问大家可以留言交流,谢谢大家对的支持
免责声明:本站资源来自互联网收集,仅供用于学习和交流,请遵循相关法律法规,本站一切资源不代表本站立场,如有侵权、后门、不妥请联系本站删除!
更新日志
- 【原神】V5.0攻略 | 林尼攻略一图流
- 李翊君.1993-相思的烈酒【上华】【WAV+CUE】
- 古巨基.1998-LEO.KU(国)【千禧年代】【WAV+CUE】
- 郭子.2001-原来你什么都不想要创作集丫滚石】【WAV+CUE】
- 《使命召唤:黑色行动6》新预告公布!10月25日发售
- Atlus《暗喻幻想》媒体评分汇总:高分好评如潮!
- 2024金摇杆奖提名揭晓 《黑神话》角逐最佳视觉设计!
- 群星《新说唱2024 第3期 (上)》[320K/MP3][32.76MB]
- 群星《新说唱2024 第3期 (上)》[FLAC/分轨][95.38MB]
- 群星《新说唱2024 第3期 (下)》[320K/MP3][31.36MB]
- 幻兽帕鲁手游什么时候正式上线 最新消息一览
- 西普大陆BOSS位置盘点 解锁天启纪元玩法
- 西普大陆精灵进阶培养攻略 精灵养成指南
- dnf手游法控法系职业哪个强 dnf手游法控法系职业强度排行
- 魔兽世界血藤护目镜图纸在哪买 wlk血藤护目镜图纸购买位置介绍