django 实现编写控制登录和访问权限控制的中间件方法

MIDDLEWARE_CLASSES = (
  'django.contrib.sessions.middleware.SessionMiddleware',
  'django.middleware.common.CommonMiddleware',
  #'django.middleware.csrf.CsrfViewMiddleware',
  'django.contrib.auth.middleware.AuthenticationMiddleware',
  'django.contrib.auth.middleware.SessionAuthenticationMiddleware',
  'django.contrib.messages.middleware.MessageMiddleware',
  'django.middleware.clickjacking.XFrameOptionsMiddleware',
  'django.middleware.security.SecurityMiddleware',
  'myTransport.views.ExteriorAuthMiddleware',
)

class ExteriorAuthMiddleware(object):
  #判断登录 权限控制
	def process_request(self,request):
		if request.method == 'GET':
			requestData = request.GET
		else:
			requestData = request.POST		
		request.session['errmsg']=''
		#如果用户没有认证，需要转到登录界面
		if not request.session.has_key('_auth_user_id') and 'login' not in request.path:
			return HttpResponseRedirect('/login/')
		#如果用户已经登录
		elif request.session.has_key('_auth_user_id') and 'logout' not in request.path:
			###权限检验
			try:
				u=User.objects.get(username=request.user)
				#判断token是否过期
				if u.usertoken_set.all():
					if u.usertoken_set.all()[0].token != request.session['Token']:
						logger.error("token 不一致！")
						return HttpResponseRedirect('/login/')
				else:
					logger.error("获取不到token!")
					return HttpResponseRedirect('/login/')
 
				url=request.META['PATH_INFO']
				print request.get_full_path()
				#判断用户是否有某些页面的访问权限，如果没有，转到404页面
				if not u.is_superuser:
					if url.startswith('/transport/user_') or url.startswith('/log/'):
						return error403(request, "权限不够！")
			except Exception,e:
				logger.error("in function process_request :"+ str(e))
				return HttpResponseRedirect('/login/')
		#用户已登录，而且url是login,将转到首页
		if request.session.has_key('_auth_user_id') and 'login' in request.path:
			return HttpResponseRedirect('/index/')