使用Django开发简单接口：文章增删改查

[TOC]

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：