Stateful SOAP Webservices with Java and PHP
International PHP Conference 2008 – Spring Edition
Thorsten Rinne

Introduction
❙ Thorsten Rinne
❙ 31 years old
❙ Graduated in computer science
❙ Project manager at Mayflower GmbH, Munich
❙ Reporting applications
❙ Critical bank applications
❙ PHP Consulting
❙ PHP software development since 1999
❙ Founder and main developer of Open Source FAQ-
management software phpMyFAQ since 2001
❙ Zend Certified Engineer (PHP 5)
Stateful SOAP Webservices
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Summary
❙ Introduction
❙ SOAP and PHP
❙ Stateful SOAP Webservices
❙ Implemention
❙ Real world example
❙ Questions and answers
Stateful SOAP Webservices
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What is SOAP?
❙ SOAP is a protocol for exchanging XML-based messages
over computer networks
❙ It uses HTTP, HTTPS or SMTP
❙ SOAP is the successor of XML-RPC
❙ Advantages
❙ using SOAP over HTTP allows for easier communication
through proxies and firewalls
❙ platform independent
❙ language independent
❙ Disadvantages
❙ Slower than technologies like CORBA
❙ Bad performance with binary data
Stateful SOAP Webservices
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A simple SOAP message
❙ Simple structure of a SOAP message
<?xml version=\"1.0\"?>
<s:Envelope
xmlns:s=\"http://www.w3.org/2001/12/soap-envelope\">
<s:Header>
</s:Header>
<s:Body>
</s:Body>
</s:Envelope>
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Using SOAP with PHP
❙ ext/soap can be used to write SOAP servers and clients
❙ Support of subsets of SOAP 1.1, SOAP 1.2 and WSDL 1.1
specifications
❙ No built-in support for WS-Addressing!
❙ SOAP server
$server = new SoapServer('some.wsdl',
array('soap_version' => SOAP_1_2));
❙ SOAP client
$client = new SoapClient('some.wsdl',
array('soap_version' => SOAP_1_2));
Stateful SOAP Webservices
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Stateful SOAP Webservices
❙ By default, SOAP webservices are stateless
❙ A stateful SOAP webservice is a webservice that maintains state
information between message calls
❙ Session ID is stored in the SOAP header with WS-Addressing (WS-A)
❙ How do stateful SOAP webservices work?
❙ Request by SOAP client
CS
❙ SOAP session will be created by SOAP server
❙ Response from SOAP server to SOAP client with Session ID
CS
❙ More interaction between client and server
❙ Used in mulit-user environments with multiple requests/responses
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Implementation
Apache Axis2 example:
<wsa:ReplyTo>
<wsa:Address>
http://www.w3.org/2005/08/addressing/anonymous
</wsa:Address>
<wsa:ReferenceParameters>
<axis2:ServiceGroupId xmlns:axis2=
\"http://ws.apache.org/namespaces/axis2\">
urn:uuid:65E9C56F702A398A8B11513011677354
</axis2:ServiceGroupId>
</wsa:ReferenceParameters>
</wsa:ReplyTo>
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PHP implementation
❙ ext/soap doesn‘t support SOAP sessions
❙ Would be possible with WSO2 Web Services
Framework/PHP (WSO2 WSF/PHP) extension
❙ We have to overwrite the
SoapClient::__doRequest() method from PHP to
implement WS-Addressing support
❙ First, we have to add a WS-A class written by Rob Richards
(http://www.cdatazone.org/files/soap-wsa.phps)
❙ Parses to the SOAP XML header
❙ Sets the session ID
❙ Also support for WS-Security (WS-S) if needed
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PHP implementation (I)
class MyProject_SOAPClient extends SoapClient
{
public function __doRequest($request, $location, $saction, $version)
{
$dom = new DOMDocument();
$dom->loadXML($request);
$wsasoap = new WSASoap($dom);
$wsasoap->addAction($saction);
$wsasoap->addTo($location);
$wsasoap->addMessageID(); // Sets the session ID
$wsasoap->addReplyTo();
$request = $wsasoap->saveXML();
return parent::__doRequest($request, $location, $saction, $version);
}
}
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PHP implementation (II)
class OurService {
/* … */
$axis2session = $this->_getSoapSession($this->soapClient->__getLastResponse());
$soapHeader = new SoapHeader('http://ws.apache.org/namespaces/axis2',
'ServiceGroupId',$axis2session);
$this->soapClient->__soapCall('getData', array(), null, $soapHeader);
/* … */
private function _getSoapSession($response) {
$soapsession = '';
$xml = new XMLReader();
$xml->XML($response);
while ($xml->read()) {
if (strpos($xml->name, 'axis2:ServiceGroupId') !== false) {
$xml->read();
$soapsession = $xml->value;
$xml->read();
}
}
return $soapsession;
}
Stateful SOAP Webservices
}
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Welcome to the real world
❙ Various applications based on
❙ Java (main application)
❙ Excel with a included DLL written in C++
❙ Access/Visual Basic
❙ Web application in PHP (our project)
❙ All applications were using the same calculation logic but
implemented in different programming language
❙ Big problems when the logic changes
❙ Solution
❙ Migration of the Access tool into the PHP application
❙ Build a SOAP service on top of the Java classes
❙ Replace the C++ written library and our PHP based library
with the SOAP webservice
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Welcome to the real world!
Old architecture
Microsoft Office Client PC
Microsoft Access and Excel
mod_php
MySQL
Apache 2.0
Linux
J2EE Cluster (Calculation engine) Stateful SOAP Webservices
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Welcome to the real world!
Current architecture
J2EE Cluster (Calculation engine)
Microsoft Office Client PC
Transfer by SFTP
SOAP over HTTPS
SOAP
SOAP
mod_php
Axis2
java.class
MySQL
Apache 2.0
Tomcat 5.5
Linux
Stateful SOAP Webservices
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Questions and answers
Stateful SOAP Webservices
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Thank you very much!
Thorsten Rinne, Dipl.-Inf. (FH)
Mayflower GmbH
Mannhardtstraße 6
D-80538 München
Germany
+49 (89) 24 20 54 – 31
thorsten.rinne@mayflower.de