环境
中间件作用 中间件用于全局修改Django的输入或输出。
中间件常见用途
中间件执行流程
全局异常捕捉实现
创建django项目&添加app
django-admin startproject middleware cd middleware django-admin startapp app
添加app到项目
# middleware/settings.py # INSTALLED_APPS最后添加 app INSTALLED_APPS = [ 'app', ]
编辑中间件并添加到项目
注：中间件注册访问有一定的关联性，位置不可以随意放
# 创建app/middleware.py并编辑
from django.http import JsonResponse
class CustomMiddleware:
def __init__(self, get_response):
print("程序启动时执行, 只执行一次")
self.get_response = get_response
def __call__(self, request):
print("中间件开始")
response = self.get_response(request)
print("中间件结束")
return response
def process_view(self, request, view_func, view_args, view_kwargs):
print("请求实际函数前执行")
def process_exception(self, request, exception):
print("程序异常时执行")
return JsonResponse({"msg": exception.args[0], "code": -1})
编辑middleware.setttings.py
MIDDLEWARE = [ ... 'app.middleware.CustomMiddleware' ]
编写一个异常
# app/views.py
from django.http import JsonResponse
def json_response(request):
print('json_response')
err = 3 / 0
return JsonResponse({"msg": "ok", "code": 0})
添加到路由
# middleware/urls.py
from app.views import json_response, view_response
urlpatterns = [
...
path("view", view_response)
]
运行测试
访问: http://127.0.0.1:8000/json/
结果
另一个觉用途日志记录
# 在中间件函数process_view中添加
print("path: {}; method: {}; data: {}".format(request.get_full_path(), request.method, request.body or ''))
参考: https://docs.djangoproject.com/zh-hans/2.1/topics/http/middleware/
