如何使用php编写soap Web服务，错误：看起来我们没有XML文档

我不熟悉soap Web服务。我用php语言编写了一个服务器和一个客户机文件，我遇到了这样的输出：看起来我们没有XML文档

soap_server.php：

<?php require_once ('lib/nusoap.php'); 
$namespace = "http://localhost/webservice/soap_server.php?wsdl";
$server = new soap_server();
$server->configureWSDL("webservice");
$server->wsdl->schemaTargetNamespace = $namespace;
//register a function that works on server 
$server->register('get_message'); 

// create the function 
function get_message($your_name) 
{ 
if(!$your_name){ 
return new soap_fault('Client','','Put Your Name!'); 
    //echo "no name"
} 
$result = "Welcome to ".$your_name .". Thanks for Your First Web Service Using PHP with SOAP"; 
return $result; 
} 

//create HTTP listener 
$HTTP_RAW_POST_DATA = isset($HTTP_RAW_POST_DATA) ? $HTTP_RAW_POST_DATA : '';
$server ->service($HTTP_RAW_POST_DATA);
exit();
?>

输出：

此XML文件似乎没有任何与之关联的样式信息。文档树如下所示。

<?php require_once ('lib/nusoap.php'); 
//Give it value at parameter 
$param = array( 'your_name' => 'Monotosh Roy'); 
$url='http://localhost/webservice/soap_server.php?wsdl';
// echo file_get_contents($url); 
//Create object that referer a web services 
try
{
    $client = new SoapClient($url); 

//Call a function at server and send parameters too

$response = $client->get_message($param); 
var_dump($response);
echo "ok";
}
catch(SoapFault $e)
{
    echo "nok";
  print_r($e);
}

 nokSoapFault Object
(
    [message:protected] => looks like we got no XML document
    [string:Exception:private] => 
    [code:protected] => 0
    [file:protected] => C:\xampp\htdocs\webservice\soap_client.php
    [line:protected] => 14
    [trace:Exception:private] => Array
        (
            [0] => Array
                (
                    [file] => C:\xampp\htdocs\webservice\soap_client.php
                    [line] => 14
                    [function] => __call
                    [class] => SoapClient
                    [type] => ->
                    [args] => Array
                        (
                            [0] => get_message
                            [1] => Array
                                (
                                    [0] => Array
                                        (
                                            [your_name] => Monotosh Roy
                                        )

                                )

                        )

                )

            [1] => Array
                (
                    [file] => C:\xampp\htdocs\webservice\soap_client.php
                    [line] => 14
                    [function] => get_message
                    [class] => SoapClient
                    [type] => ->
                    [args] => Array
                        (
                            [0] => Array
                                (
                                    [your_name] => Monotosh Roy
                                )

                        )

                )

        )

    [previous:Exception:private] => 
    [faultstring] => looks like we got no XML document
    [faultcode] => Client
    [faultcodens] => http://schemas.xmlsoap.org/soap/envelope/
)

This XML file does not appear to have any style information associated with it. The document tree is shown below.
<definitions xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/" xmlns:tns="http://localhost/soap/webservice" xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" xmlns:wsdl="http://schemas.xmlsoap.org/wsdl/" xmlns="http://schemas.xmlsoap.org/wsdl/" targetNamespace="http://localhost/soap/webservice">
<types>
<xsd:schema targetNamespace="http://localhost/soap/webservice">
<xsd:import namespace="http://schemas.xmlsoap.org/soap/encoding/"/>
<xsd:import namespace="http://schemas.xmlsoap.org/wsdl/"/>
</xsd:schema>
</types>
<message name="get_messageRequest"/>
<message name="get_messageResponse"/>
<portType name="webservicePortType">
<operation name="get_message">
<input message="tns:get_messageRequest"/>
<output message="tns:get_messageResponse"/>
</operation>
</portType>
<binding name="webserviceBinding" type="tns:webservicePortType">
<soap:binding style="rpc" transport="http://schemas.xmlsoap.org/soap/http"/>
<operation name="get_message">
<soap:operation soapAction="http://localhost/webservice/soap_server.php/get_message" style="rpc"/>
<input>
<soap:body use="encoded" namespace="" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</input>
<output>
<soap:body use="encoded" namespace="" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
</output>
</operation>
</binding>
<service name="webservice">
<port name="webservicePort" binding="tns:webserviceBinding">
<soap:address location="http://localhost/webservice/soap_server.php"/>
</port>
</service>
</definitions>