Java 如何解决SOAP中字符串未知的故障代码：soapenv:Server

我正在开发soapweb服务。我用下面的表格发送请求

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/" xmlns:q0="http://gramenerit.com/BankService/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<soapenv:Body>
   <q0:XYZDetails>
       <field name="abc">1001121</field> 
  </q0:XYZDetails>
</soapenv:Body>
</soapenv:Envelop>

1001121

但作为回应，我也有过错

<soapenv:Body>
 <soapenv:Fault>
   <faultcode>soapenv:Server</faultcode> 
   <faultstring>unknown</faultstring> 
   <detail /> 
</soapenv:Fault>

soapenv:服务器
不为人知

我的响应类型xsd是

<xsd:element name="XYZResponse">
    <xsd:complexType>
      <xsd:sequence>
        <xsd:element name="xyz_response" maxOccurs="unbounded" minOccurs="0">
          <xsd:complexType>
            <xsd:simpleContent>
              <xsd:extension base="xsd:string">
                <xsd:attribute type="xsd:string" name="name" use="optional"/>
              </xsd:extension>
            </xsd:simpleContent>
          </xsd:complexType>
        </xsd:element>
      </xsd:sequence>
    </xsd:complexType>
  </xsd:element>

我签入了服务器日志，但它没有显示任何错误。如何修复它