如何使用http post发送soap请求而不创建xml文件？

Question

我不需要创建xml文件只想发送一个soap请求：

SOAPConnectionFactory soapConnectionFactory = SOAPConnectionFactory.newInstance();

SOAPConnection soapConnection = soapConnectionFactory.createConnection();

SOAPMessage req = createSoapSubsribeRequest("SUBSCRIBE");

我需要通过httppost发送此请求。