使用Django开发简单接口实现文章增删改查

1、一些准备工作

 安装django

pip install django

创建django项目

进入项目代码存放目录执行命令：

django-admin.py startproject blog_demo

进入blog_demo，运行命令：

python3.6 manage.py runserver 9000

在浏览器地址栏打开：http://127.0.0.1:9000/ 如果出现以下画面，则说明服务器正在运行

创建博客应用（app）

django中每一个app可以看作是一个模块，以app为单位，结构清晰，方便管理。

python3.6 manage.py startapp blog_api

使用开发工具打开项目blog_demo，其结构如下：

2、models.py

编写模型层代码，以下语句相当于创建了两张表：User，Article

class User(models.Model):
  id = models.AutoField(primary_key=True)
  uname = models.CharField(max_length=50)
  upwd = models.CharField(max_length=100)
  #active inactive
  status = models.CharField(max_length=10)

class Article(models.Model):
  id = models.AutoField(primary_key=True)
  title = models.CharField(max_length=50)
  content = models.TextField()
  #deleted alive
  status = models.CharField(max_length=10)

创建表结构：

python3.6 manage.py migrate

settings.py文件INSTALLED_APPS处新增app：blog_api

INSTALLED_APPS = [
  'django.contrib.admin',
  'django.contrib.auth',
  'django.contrib.contenttypes',
  'django.contrib.sessions',
  'django.contrib.messages',
  'django.contrib.staticfiles',
  'blog_api'
]

让django知道模型有了变化：

python3.6 manage.py makemigrations blog_api

再次创建表结构：

python3.6 manage.py migrate

3、django admin

 登录

在浏览器控制台输入：http://127.0.0.1:9000/admin/login/?next=/admin/

创建超级用户

stephen@stephen-K55VD:~/IdeaProjects/blog_demo$ python3.6 manage.py createsuperuser 
Username (leave blank to use 'stephen'): admin
Email address: 
Password: 
Password (again): 
This password is too common.
Bypass password validation and create user anyway? [y/N]: y
Superuser created successfully.

邮件地址可以不填，注册成功后即可登录。使用admin后台来管理模型需要先注册，修改blog_api/admin.py代码

#导入模型User,Article
from blog_api.models import User,Article

admin.site.register(User)
admin.site.register(Article)

刷新admin后台，就可以看到刚刚注册的模型了。

4、修改urls.py

from blog_api.views import add_article,modify_article
urlpatterns = [
  path('admin/', admin.site.urls),
  path('articles/',add_article),
  path('articles/<int:art_id>',modify_article)
]

5、新增文章接口

from django.http import HttpResponse,JsonResponse
from blog_api.models import User,Article
import json

#新增文章
def add_article(request):
  if request.method == "POST":
    req = json.loads(request.body)
    print (req)
    key_flag = req.get("title") and req.get("content") and len(req)==2
    #判断请求体是否正确
    if key_flag:
      title = req["title"]
      content = req["content"]
      #title返回的是一个list
      title_exist = Article.objects.filter(title=title)
      #判断是否存在同名title
      if len(title_exist) != 0:
        return JsonResponse({"status":"BS.400","msg":"title aleady exist,fail to publish."})

      '''插入数据'''
      add_art = Article(title=title,content=content,status="alive")
      add_art.save()
      return JsonResponse({"status":"BS.200","msg":"publish article sucess."})
    else:
      return JsonResponse({"status":"BS.400","message":"please check param."})

使用postman工具调用接口，运行结果：

6、查询文章接口

#查询所有文章和状态
  if request.method == "GET":
    articles = {}
    query_art = Article.objects.all()
    for title in query_art:
      articles[title.title] = title.status
    return JsonResponse({"status":"BS.200","all_titles":articles,"msg":"query articles sucess."})

运行结果：

7、修改文章接口

#修改文章
def modify_article(request,art_id):
  if request.method == "POST":
    req = json.loads(request.body)
    try:
      art = Article.objects.get(id=art_id)
      key_flag = req.get("title") and req.get("content") and len(req)==2
      if key_flag:
        title = req["title"]
        content = req["content"]
        title_exist = Article.objects.filter(title=title)
        if len(title_exist) > 1:
          return JsonResponse({"status":"BS.400","msg":"title aleady exist."})
        '''更新数据'''
        old_art = Article.objects.get(id=art_id)
        old_art.title = title
        old_art.content = content
        old_art.save()
        return JsonResponse({"status":"BS.200","msg":"modify article sucess."})
    except Article.DoesNotExist:
      return JsonResponse({"status":"BS.300","msg":"article is not exists,fail to modify."})

运行结果：

8、删除文章接口

#删除文章
  if request.method == "DELETE":
    try:
      art = Article.objects.get(id=art_id)
      art_id = art.id
      art.delete()
      return JsonResponse({"status":"BS.200","msg":"delete article sucess."})
    except Article.DoesNotExist:
      return JsonResponse({"status":"BS.300","msg":"article is not exists,fail to delete."})

运行结果：

9、鉴权

四个简单的接口已经可以运行了，但是在发请求之前没有进行鉴权，毫无安全性可言。下面来实现简单的认证机制。需要用到内建模块hashlib，hashlib提供了常见的摘要算法，如MD5，SHA1等。

鉴权接口

新增一个专门用于鉴权的接口。在urls.py中添加

path("auth/",get_token)

在views.py前面新增函数get_token(request)

import hashlib

#获取token
def get_token(request):
  req = json.loads(request.body)
  uname = req["username"]
  upwd = req["password"]
  if request.method == "POST":
    try:
      tmppwd =User.objects.get(uname=uname).upwd
      if upwd == tmppwd:
        md5 = hashlib.md5()
        #把密码变成一个长度固定的字符串
        md5.update(upwd.encode("utf-8"))
        return JsonResponse({"status":"BS.201","X-Token":md5.hexdigest()})
      else:
        return JsonResponse({"status":"BS.401","msg":"username or password may wrong."})

    except User.DoesNotExist:
      return JsonResponse({"status":"BS.500","msg":"username is not exist."})

登录django admin在blog_api下的User表新增一条记录。运行结果：

用户认证

request.META.get(“header key”) 用于获取header的信息。注意的是header key必须增加前缀HTTP，同时大写，中划先会转成下划线，例如你的key为X-Token，那么应该写成request.META.get("HTTP_X_TOKEN")，修改views.py在get_token后面加上如下代码：

#认证动作
def user_auth(request):

  token = request.META.get("HTTP_X_TOKEN",b'')
  print (token)
  if token:
    #暂时先写上auth接口返回的数据
    if token=="0a6db4e59c7fff2b2b94a297e2e5632e":
      return "auth_sucess"
    else:
      return "auth_fail"
  else:
    return "auth_fail"

在接口中调用user_auth函数，以发布文章接口为例：

#新增文章
def add_article(request):
  auth_res = user_auth(request)
  if auth_res == "auth_fail":
    return JsonResponse({"status":"BS.401","msg":"user auth failed."})
  else:
    if request.method == "POST":
      req = json.loads(request.body)
      print (req)
      .......

再次使用postman工具调用新增文章接口，Header中没有X-Token或X-Token错误时的运行结果：