03.创建订单并生成支付链接接口

1..创建订单并生成支付链接接口

---

1.1 goods/urls.py中注册路由

urlpatterns = [ 
     path('getpayurl/', views.PayUrlView.as_view()), # /goods/getpayurl/ 
]

1.2 goods/views.py 中写视图函数

from rest_framework.views import APIView 
from rest_framework.permissions import AllowAny, IsAuthenticated 
from rest_framework.response import Response 
from .models import Goods,Orders,GoodsCourse 
from goods.utils import get_order_id, get_pay_url, alipay


# 创建订单并生成支付链接接口
class PayUrlView(APIView):
    permission_classes = (IsAuthenticated,)  # 用户权限

    def post(self, request):
        # 1. 获取课程id,获取购买途径(普通购买, 促销购买) 获取用户
        goods_id = request.data.get('goods_id')
        if not goods_id:
            return Response({'msg': '参数不全'})
        goods = Goods.objects.get(id=goods_id)
        user = request.user

        # 2.下订单 判断会员并打折
        order_id = get_order_id()
        if user.vip.vip_type == '1':  # 普通会员
            goods_price = goods.price * Decimal('0.80').quantize(Decimal('0.00'))

        elif user.vip.vip_type == '2':  # 高级会员
            goods_price = goods.price * Decimal('0.60').quantize(Decimal('0.00'))

        else:
            goods_price = goods.price
        goods_price = Decimal(goods_price).quantize(Decimal('0.00'))

        order = Orders(user=user, goods=goods, order_id=order_id, pay_method=1, status=1, total_amount=goods_price)
        order.save()
        print(order.total_amount, type(order.total_amount))

        # 3. 根据订单 生成支付链接
        subject = "实验楼订单:%s, 价格:%s" % (order.order_id, order.total_amount)
        pay_url = get_pay_url(order.order_id, order.total_amount, subject)

        # 4. 返回链接
        return Response({"code": 0, "msg": "下单成功", "data": {"pay_url": pay_url}})

(~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~)
注意啊：踩过的坑，涉及金融计算，涉及小数啊，要求特别精确的，我们用字符串存储。

如果是金融计算的话，我们用一个decimal来进行计算。
(~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~)

1.3 goods/utils.py中生成随机订单函数和生成支付URL函数

# -*- coding: utf-8 -*-
import datetime
import os
import random
from alipay import AliPay
from django.conf import settings

# 获取文件路径
app_private_key_path = os.path.join(settings.BASE_DIR, "apps/goods/keys/app_private_key.pem")
alipay_public_key_path = os.path.join(settings.BASE_DIR, "apps/goods/keys/alipay_public_key.pem")
with open(app_private_key_path) as f:
    app_private_key_string = f.read()
with open(alipay_public_key_path) as f:
    alipay_public_key_string = f.read()

# 创建支付宝支付对象
alipay = AliPay(
    appid=settings.ALIPAY_APPID,
    app_notify_url=None,  # 默认回调url
    app_private_key_string=app_private_key_string,
    alipay_public_key_string=alipay_public_key_string,
    # app_private_key_path=app_private_key_path,
    # alipay_public_key_path=alipay_public_key_path,
    sign_type="RSA2",
    debug=settings.ALIPAY_DEBUG
)

# 生成登录支付宝连接
def get_pay_url(out_trade_no, total_amount, subject):  
    order_string = alipay.api_alipay_trade_page_pay(
        out_trade_no=out_trade_no,
        total_amount=str(total_amount),
        subject=subject,
        return_url=settings.ALIPAY_RETURN_URL,
    )
    # 响应登录支付宝连接
    # 真实环境电脑网站支付网关：https://openapi.alipay.com/gateway.do? + order_string
    # 沙箱环境电脑网站支付网关：https://openapi.alipaydev.com/gateway.do? + order_string
    alipay_url = settings.ALIPAY_URL + "?" + order_string
    return alipay_url

#生成订单号:
def get_order_id():
    """
    SYL202008241212121200005/24
    生成订单号: 格式: SYL + 年月日时分秒 + 5位随机数
    :return:
    """
    d = datetime.datetime.now()
    base = 'SYL'
    time_str = '%04d%02d%02d%02d%02d%02d' % (d.year, d.month, d.day, d.hour, d.minute, d.second)
    rand_num = str(random.randint(10000, 99999))
    return base + time_str + rand_num

1.4 syl/setings.py中配置支付相关参数

# 支付宝配置
ALIPAY_APPID = '2016102600762673' # 沙箱环境中alipay应用ID  自己的应用ID
ALIPAY_DEBUG = True
ALIPAY_URL = 'https://openapi.alipaydev.com/gateway.do' # alipay沙箱环 境支付宝网管
ALIPAY_RETURN_URL = 'http://127.0.0.1:8888/payment/callback/' # 支付完成后支 付宝回调我们应用的地址

2.测试

---

• 请求地址

http://192.168.56.100:8888/goods/getpayurl/

• 携带参数

{ 
     "goods_id":1 
}

• 返回参数

{
    "code":0,
    "msg":"下单成功",
    "data":{
        "pay_url":"https://openapi.alipaydev.com/gateway.do?app_id=2016102600762673&biz_content=%7B%22subject%22%3A%22%5Cu5b9e%5Cu9a8c%5Cu697c%5Cu8ba2%5Cu5355%3ASYL2020101512171797508%2C+%5Cu4ef7%5Cu683c%3A532.80%22%2C%22out_trade_no%22%3A%22SYL2020101512171797508%22%2C%22total_amount%22%3A%22532.80%22%2C%22product_code%22%3A%22FAST_INSTANT_TRADE_PAY%22%7D&charset=utf-8&method=alipay.trade.page.pay&return_url=http%3A%2F%2F127.0.0.1%3A8888%2Fpayment%2Fcallback%2F&sign_type=RSA2×tamp=2020-10-15+12%3A17%3A17&version=1.0&sign=HFBOqgSdbqstvFFur9oBEwZuYT7eK30pE6zJ14CWjQPcvrkOylz2%2FOwLnPk7cUtwzU3R1O3hMq24H3VCzj2PIsVQazAlsbUrmm9Jaoliac%2FmpVXqZ7ERJYfzcse7UU4k0f%2FCgjj3lWqjHRuiE8tRdEdVdtl8aJKpRlkhrH4WbuTV8Ej3Hy%2Fkt9KTCS%2B6mkxcu57t9%2FgecPhcUweh%2FKWEFVv1A3owBjb%2BiqtemgAOVJ0NtxjfUbzr8poNVtKMjT%2Bw4aanvizwAIEoJsM9TNt1AtP%2BukAW8q7bTY6RFcl%2BhgJCtcUmeqyKTyUsnqjfkassA9sQj6P8K53CbFJLFoSyBA%3D%3D"
    }
}