Django集成PhonePe支付遇多类错误，请求排查并调出支付界面

我在Django项目中集成PhonePe支付时，出现了Service unavailable、internal server error错误，并且在pay函数的responseData = response.json()这一行触发了JSONDecodeError。目前只希望能成功调出支付界面，不确定错误出自我的代码还是PhonePe端，相关代码如下：

def calculate_sha256_string(input_string):
    # Create a new SHA-256 hash object
    sha256 = SHA256.new()
    # Update hash with the encoded string
    sha256.update(input_string.encode('utf-8'))
    # Return the hexadecimal representation of the hash
    return sha256.hexdigest()

def base64_encode(input_dict):
    # Convert the dictionary to a JSON string
    json_data = jsons.dumps(input_dict)
    # Encode the JSON string to bytes
    data_bytes = json_data.encode('utf-8')
    # Perform Base64 encoding and return the result as a string
    return base64.b64encode(data_bytes).decode('utf-8')

def pay(request):
    MAINPAYLOAD = {
        "merchantId": "PGTESTPAYUAT",
        "merchantTransactionId": shortuuid.uuid(),
        "merchantUserId": "MUID123",
        "amount": 10000,
        "redirectUrl": "http://127.0.0.1:8000/return-to-me",
        "redirectMode": "POST",
        "callbackUrl": "http://127.0.0.1:8000/return-to-me",
        "mobileNumber": "9999999999",
        "paymentInstrument": {
            "type": "PAY_PAGE"
        }
    }
    # SETTING
    INDEX = "1"
    ENDPOINT = "/pg/v1/pay"
    SALTKEY = "099eb0cd-02cf-4e2a-8aca-3e6c6aff0399"
    base64String = base64_encode(MAINPAYLOAD)
    mainString = base64String + ENDPOINT + SALTKEY
    sha256Val = calculate_sha256_string(mainString)
    checkSum = sha256Val + '###' + INDEX
    print("Checksum:", checkSum)
    # Payload Send
    headers = {
        'accept': 'application/json',
        'Content-Type': 'application/json',
        'X-VERIFY': checkSum
    }
    payload = {
        'request': base64String
    }
    print("Sending request to PhonePe API:")
    print("URL:", 'https://api-preprod.phonepe.com/apis/pg-sandbox/pg/v1/pay')
    print("Headers:", headers)
    print("Payload:", payload)
    response = requests.post('https://api-preprod.phonepe.com/apis/pg-sandbox/pg/v1/pay', headers=headers, json=payload)
    print("Raw Response Content:")
    print(response.text)
    responseData = response.json() #getting error here
    print("Response from PhonePe API:")
    print(responseData)

    # Print the raw response content

    redirect_url = responseData['data']['instrumentResponse']['redirectInfo']['url']
    print("Redirect URL:", redirect_url)

    return redirect(redirect_url)

def payment_return(request):

    INDEX = "1"
    SALTKEY = "099eb0cd-02cf-4e2a-8aca-3e6c6aff0399"
    form_data = request.form
    form_data_dict = dict(form_data)
    # respond_json_data = jsonify(form_data_dict)
    # 1.In the live please match the amount you get byamount you send also so that hacker can't pass static value.
    # 2.Don't take Marchent ID directly validate it with yoir Marchent ID
    if request.form.get('transactionId'):
        request_url = 'https://api-preprod.phonepe.com/apis/pg-sandbox/pg/v1/status/PGTESTPAYUAT/' + request.form.get('transactionId')
        sha256_Pay_load_String = '/pg/v1/status/PGTESTPAYUAT/' + request.form.get('transactionId') + SALTKEY
        sha256_val = calculate_sha256_string(sha256_Pay_load_String)
        checksum = sha256_val + '###' + INDEX
        # Payload Send
        headers = {
            'Content-Type': 'application/json',
            'X-VERIFY': checksum,
            'X-MERCHANT-ID': request.form.get('transactionId'),
            'accept': 'application/json',
        }
        response = requests.get(request_url, headers=headers)
        #print(response.text);
    return render('main/try.html', page_respond_data=form_data_dict, page_respond_data_varify=response.text)

排查关键点 #

• JSONDecodeError直接原因：当PhonePe返回非JSON格式响应（比如500错误的HTML页面）时，调用response.json()必然报错。先查看你打印的response.text内容，确认返回的是不是有效JSON。如果是HTML错误页，说明请求本身就没被正确处理。
• 序列化函数错误：base64_encode里用了jsons.dumps，应该是标准库的json.dumps（多了个s），这会导致字典序列化失败或格式不符合PhonePe要求，最终签名校验不通过，触发服务端错误。
• 签名校验逻辑：严格按照PhonePe文档核对签名计算步骤，mainString = base64String + ENDPOINT + SALTKEY的拼接顺序、字符编码必须完全正确，不能有多余的空格或换行符。
• 请求参数与端点：沙箱API端点https://api-preprod.phonepe.com/apis/pg-sandbox/pg/v1/pay是正确的，但要确保MAINPAYLOAD里的参数格式符合要求，比如amount单位是派萨（10000对应100卢比），这点你当前是对的。
• 回调地址可访问性：沙箱环境下本地127.0.0.1可以用于跳转，但如果PhonePe需要主动回调你的服务，本地开发需要用ngrok等工具暴露公网端口，否则回调会失败。
• 错误处理缺失：当前代码未处理请求失败的情况，建议先判断响应状态码再解析JSON：

  if response.status_code == 200:
      try:
          responseData = response.json()
      except JSONDecodeError:
          print("无效JSON响应:", response.text)
  else:
      print(f"请求失败，状态码: {response.status_code}，响应内容: {response.text}")
  

• return视图参数错误：payment_return里的render调用缺少第一个参数request，且上下文参数格式错误，正确写法是：

  return render(request, 'main/try.html', {
      'page_respond_data': form_data_dict,
      'page_respond_data_varify': response.text if 'response' in locals() else ''
  })
  

内容的提问来源于stack exchange，提问作者Himanshu Pandey