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B2B Application Integration Using Web Services. Nagarjuna Nagulapati Under the guidance of Dr. Daniel Andresen (Major Professor) Dr. Torben Amtoft Dr. William J. Hankley. Outline. Problem Statement Solution Application Integration Technologies B2B Application Integration & Web Services
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B2B Application Integration Using Web Services Nagarjuna NagulapatiUnder the guidance of Dr. Daniel Andresen (Major Professor)Dr. Torben AmtoftDr. William J. Hankley
Outline • Problem Statement • Solution • Application Integration Technologies • B2B Application Integration & Web Services • SOAP • SOAP Style & Encoding • Implementation • Performance Evaluation
Problem Statement • Market Globalization • Need to stay ahead of competitors • Solutions from multiple vendors • Unable to share information and isolated functionality
Solution • Application Integration(AI) • Application integration is the real-time controlled sharing of data and business processes among any connected applications and data sources within inter and intra organizations.
Advantages • Increased productivity • Controlled procurement processes • Interoperability with partners • Reuse of existing systems
Types of AI • Enterprise Application Integration • Integrating applications within an enterprise • EDI – based on ANSI standards • Point-to-point integration • B2B Application Integration • Integrating applications across enterprises • Middlewares – facilitate communication between two or more software systems • Point-to-point NOT feasible
Why Web Services? • Java Middleware Technologies • RMI, JMS - Language dependent • Distributed objects • CORBA, DCOM - Platform dependent • Message Brokers • Require sweeping changes in participating applications and hence expensive • Open standards, platform and language independent, loosely-coupled integration
B2B AI and Web Services • Organizations favoring open standard protocols • XML becoming lingua franca for data formatting and interpretation • Web Services are XML-based middleware built on open standards
Web Services • Web services are middleware components that implement business logic via services and expose these services programmatically over the web, which could be invoked by service clients using SOAP over HTTP • Based on open standards like UDDI, WSDL, SOAP, XML, HTTP • Separation of specification from implementation
Web Services Stack • Transport protocol – HTTP, SMTP • Data encoding – XML • Standard Message Structure – SOAP • Service Description – WSDL • Service Discovery - UDDI
Web Services Framework Points to service UDDI WSDL description Describes service Publishes service Finds service Web Service Client SOAP HTTP proxy
SOAP • Simple Object Access Protocol, a lightweight, message-based protocol built on XML and standard Internet protocols, such as HTTP and SMTP for information exchange in a decentralized environment • Defines specification for message structure and data encoding • Facilitates structured and typed messages to be exchanged
SOAP • SOAP message must contain a SOAP envelope, a SOAP body and optional SOAP header • Encoding - serialization of data inside a SOAP message • SOAP encoding is based on XML Schemas and relies on the XML Schema data types, namespace and the type attribute
SOAP <soap:envelope> <soap:header> ………………… </soap:header> <soap:body> <add> <num1 xsi:type="xsd:int">5</num1> <num2 xsi:type="xsd:int">10</num2> </add> </soap:body> </soap:envelope> SOAP header Sequence numbers, authentication credentials SOAP envelope SOAP payload Container to hold the SOAP message Method calls, parameters, Application-specific data
WSDL • Describes Web Service methods to heterogeneous clients in a platform and language independent manner • SOAP toolkits generate proxy classes using WSDL • Service contract which specifies the methods available and type information needed to properly compose SOAP requests
WSDLpublic int add(int num1, int num2) <?xml version="1.0" encoding="utf8" ?> <definitions> <types/> <message name="addSoapIn"> <partname="num1" type="s:int" /> <partname="num2" type="s:int" /> </message> <message name="addSoapOut"> <partname="addResult" type="s:int" /> </message> <portType name="sampleSoap"> <operation name="add"> <inputmessage="tns:addSoapIn" /> <outputmessage="tns:addSoapOut" /> </operation> </portType> <binding name="sampleSoap" type="tns:sampleSoap"> <soap:bindingtransport="http://schemas.xmlsoap.org/soap/http" style="rpc" /> <operation name="add"> <soap:operationsoapAction="http://tempuri.org/add" style="rpc" /> <input> <soap:bodyuse="encoded" namespace="http://tempuri.org/" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" /> </input> <output> <soap:bodyuse="encoded" namespace="http://tempuri.org/" encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" /> </output> </operation> </binding> <service name=“Sample"> <port name="sampleSoap" binding="tns:sampleSoap"> <soap:addresslocation="http://agena.cis.ksu.edu:8080/axis/services/Sample" /> </port> </service> </definitions> Describes custom or complex Data types Number and type of input and output parameters Methods available along with input and output messages Describes style and encoding of the SOAP messagesfor each operation Describes entry points to web serviceHTTP-POST, HTTP-GET, SOAP
Implementation • Web Services feasibility in integrating heterogeneous applications • B2B application modeling online trading system’s supply chain management • Web Services integrate the business processes of participating applications in a real-time fashion
System Architecture Publisher(.NET) Web Service SOAP OVER HTTP Purchaser(.NET) VENDOR(J2EE) Web Service Web Service
Technologies used • ASP.NET, ADO.NET, C# • ASP.NET WebMethod Framework • J2EE 1.3.1, EJB • AXIS 1.1 Framework • JBOSS 3.2.1 • XDoclet • IIS 5.0 • Microsoft ACT
Message Flow Purchaser Vendor Publisher orderAvailability() Delegates request to EJBwhich processes the request orderAvailabilityResponse confirmRequest() orderInvoice Inserts order into database invoiceConfirmation orderInvoice
Detailed System Architecture Publisher (.NET) IIS Server Database Unmarshalls SOAP message tonative .NET method calls .NET web service JBOSS Application Server IIS Server Business tier J2EE web service SOAP/HTTP Database proxy EJB Purchaser (.NET) Vendor (J2EE) EJB .NET web service Unmarshalls SOAP message to native Java method calls Marshalls native .NET method calls to XML
Class Diagram RPC-Style ~1200 LOC Document-Style ~1350 LOC Publisher Module 2 classes Web Services Purchaser Module12 classes Vendor Module 8 classes
SOAP processing in .NET IIS SERVER ASP.NET Web Service Handler HTTP Handler ASP.NET Engine Service Object SOAP Request XmlSerializer SOAP Response HTTP modules
SOAP processing in AXIS JBOSS APPLICATION SERVER JETTY WEB SERVER SOAP MESSAGE PROCESSOR WS CONTAINER EJB’S HTTP Handler Handlers SERVICE provider SOAP Request SOAP Response Serialization Framework Web service Handlers Axis engine
SOAP style & encoding • RPC/Encoded • One-to-one mapping between SOAP payload elements and service method • Encoding is based on Section 5, SOAP specification • SOAP framework handles (de)serializing of method calls to/from XML • Application developer deals with native objects
SOAP style & encoding • Document/Literal • No one-to-one mapping between SOAP payload and service method • SOAP payload can contain arbitrary XML • Encoding is based on the XML schema agreed upon by both parties • Application developer deals with raw SOAP payload
RPC (Vs) Document-style • public int add(int num1, int num2) <soapenv:body> <ns:add> <num1 xsi:type=“xsd:int”>10</num1> <num2 xsi:type=“xsd:int”>8</num2> </ns:add> </soapenv:body> --------------------------------------------------------------------------------------- • public Document add(Document operation) <soapenv:body> <ns:operation> <add>10</add> <add>8</add> <multiply>1</multiply> <multiply>2</multiply> </ns:operation> </soapenv:body> Method name parameter parameter Arbitrary XML
Performance Evaluation • SOAP payload (Vs) Processing time ASPWEB Windows Box Dual processor 292 MHz, 512MB Agena Solaris Box 360 MHz, 128MB
Performance Evaluation • SOAP payload (Vs) Requests/Sec
Results analysis • Results • RPC/Encoded solution performed better than Document/Literal solution • Theoretically Document/Literal should perform better • Analysis • Implementation was limited to simple data types in RPC/Encoded • Document/Literal solutions perform better for complex data types • Axis serialization (vs) Custom serialization • SAX (Vs) DOM
Lessons learned • Service-oriented application development in both .NET and J2EE • Better understanding of SOAP protocol, message structure, encoding and SOAP message processing in .NET and Apache AXIS frameworks • Application integration technologies currently being used in enterprises and how they work.
Implementation issues • Insufficient reference resources on the Document-styled Web services • Interoperability between .NET and J2EE technologies still in its nascent stages • Working simultaneously with both .NET based API’s and Java based API’s
Conclusion • SOAP is text-based, Web Service calls may be too slow for applications that require frequent and fast communications • Web Services are not suitable for applications which need to access wide variety of objects and classes
Future work • Security is utmost concern • Authentication credentials in SOAP headers • User/Passwd, Security tokens and SSL • Encoded NOT encrypted • Consortia and organizations working towards the interoperability and security of Web Services : WS-I & WS-Security
References • www.msdn.com • http://ws.apache.org/axis • http://java.sun.com/blueprints/webservices/using/webservbp3.html • http://nagoya.apache.org/wiki/apachewiki.cgi?AxisProjectPages/DotNetInterop • http://www.gotdotnet.com/team/XMLwebservices/gxa_overview.aspx • http://www.aei.on.ca/index.php/aei/notes/edi • http://ecommerce.about.com/cs/b2bresources/a/aa080108a.htm • http://www.topxml.com/b2b/articles/ts4b2b/default.asp • http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnpag/html/eappint-ch01.asp • http://www.darc.com/software/2ndLevelArt/News/Application_Integration_for_E-Business.pdf • http://www-900.ibm.com/developerWorks/cn/xml/developerConf/ • http://www-106.ibm.com/developerworks/webservices/library/ws-whichwsdl/ • http://www.jboss.org/index.html?module=bb • www.msdn.com/newsgroups
Acknowledgements • Dr. Daniel Andresen • Dr. Torben Amtoft • Dr. William J. Hankley • Sterling Hanenkamp • Travis Bradshaw