基于WSDL的简易计算器Postman请求失败问题求助

我是Postman和Web服务的新手，正尝试通过Postman结合WSDL实现一个简易计算器Web服务，但不清楚如何通过Postman的Body或Header发送请求。已尝试配置Header参数，但仍无法使服务正常运行，请求排查原因及解决方法。

我的Python服务代码： #

from spyne import Application, rpc, ServiceBase, Integer, Double
from spyne.protocol.soap import Soap11
from spyne.server.wsgi import WsgiApplication

class CalculatorService(ServiceBase):

    @rpc(Integer, Integer, _returns=Integer)
    def addition(ctx, a, b):
        return a + b

    @rpc(Integer, Integer, _returns=Integer)
    def substraction(ctx, a, b):
        return a - b

    @rpc(Integer, Integer, _returns=Integer)
    def multiplication(ctx, a, b):
        return a * b

    @rpc(Integer, Integer, _returns=Double)
    def division(ctx, a, b):
        return a / b


application = Application([CalculatorService], 'services.calculator.soap',
                          in_protocol=Soap11(validator='lxml'),
                          out_protocol=Soap11())

wsgi_application = WsgiApplication(application)

if __name__ == '__main__':
    import logging

    from wsgiref.simple_server import make_server

    logging.basicConfig(level=logging.INFO)
    logging.getLogger('spyne.protocol.xml').setLevel(logging.INFO)

    logging.info("listening to http://127.0.0.1:8000")
    logging.info("wsdl is at: http://127.0.0.1:8000/?wsdl")

    server = make_server('127.0.0.1', 8000, wsgi_application)
    server.serve_forever()

排查及解决方法： #

1. 先确认服务正常运行

运行上述Python代码后，访问http://127.0.0.1:8000/?wsdl，能看到完整的WSDL文档，说明服务启动成功。

2. Postman核心配置步骤

SOAP服务对请求格式有严格要求，以下是正确配置：

• 请求方法与URL：选择POST，URL填写http://127.0.0.1:8000/
• Header配置：必须添加Content-Type: text/xml; charset=utf-8，这是SOAP请求的必填头，也是最容易出错的点
• Body配置：选择raw格式，下拉框选XML，然后按照WSDL定义的结构编写请求体

3. 示例请求体（以addition方法为例）

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ser="services.calculator.soap">
   <soapenv:Header/>
   <soapenv:Body>
      <ser:addition>
         <ser:a>5</ser:a>
         <ser:b>3</ser:b>
      </ser:addition>
   </soapenv:Body>
</soapenv:Envelope>

4. 常见错误排查

• 检查Content-Type是否正确：不要使用application/json或其他类型，必须是text/xml
• 确认XML命名空间：xmlns:ser="services.calculator.soap"必须和代码中Application的第二个参数一致
• 参数标签匹配：方法名（如addition）、参数名（如a、b）要和WSDL定义的完全一致，注意大小写
• 端口占用：确保8000端口未被其他程序占用，可通过修改代码中的端口号测试

5. 其他方法请求示例

减法（substraction）：

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ser="services.calculator.soap">
   <soapenv:Header/>
   <soapenv:Body>
      <ser:substraction>
         <ser:a>10</ser:a>
         <ser:b>4</ser:b>
      </ser:substraction>
   </soapenv:Body>
</soapenv:Envelope>

乘法（multiplication）：

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ser="services.calculator.soap">
   <soapenv:Header/>
   <soapenv:Body>
      <ser:multiplication>
         <ser:a>6</ser:a>
         <ser:b>7</ser:b>
      </ser:multiplication>
   </soapenv:Body>
</soapenv:Envelope>

除法（division）：

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:ser="services.calculator.soap">
   <soapenv:Header/>
   <soapenv:Body>
      <ser:division>
         <ser:a>12</ser:a>
         <ser:b>3</ser:b>
      </ser:division>
   </soapenv:Body>
</soapenv:Envelope>

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