WEB-ENABLE POWERBUILDER APPS WITH SYBASE EASERVER ...

F R O M S Y B A S EWRITTEN BYSCOTT MCREYNOLDSSybase EAServer 4.1 –Web Services Enabled, J2EE 1.3 CertifiedAUTHOR BIOScott McReynolds worksin Sybase engineering onEAServer and is amember of the “SWAT”team. He has worked atSybase for six years andis a CPD, CPI. He’s usedPowerBuilder sinceversion 3.0.When Sybase released EAServer 4.0,it provided most of the J2EE functionalityfor the 1.3 specification, as well asperformance and usability enhancements.EAServer 4.1 is not only J2EE1.3–certified, but it also includes therequired technology for the next wave ofe-business – Web services.J2EE 1.3 CompatibilityThere’s a lot of talk about J2EE compatibility,but most folks have no ideawhat that means or what it takes. TheJava arm of Sun created a series of testscalled the Technology Core PlatformCompatibility Kit (TCK). The TCK consistsof a large number of tests (15,000+).These tests are developed to ensure thateach area of the specification is implementedin a compliant way.Why should you as a developer care?The biggest reason is that you can besure that if you write a J2EE application,you can easily move it from one vendor’sserver to another, provided the vendorhas passed the TCK. Remember thedatabase wars? It was very difficult tomove from one vendor to anotherbecause each one created their own setof functions and processes, even thoughthey said they supported the currentSQL standard. Since there was no test,Oracle and Sybase may each support thestandard, yet still have proprietary functions.Since the TCK has been in existence,Sybase has been among the firstvendors to pass and ship a compliantversion of its application server.Web Services EnabledWeb services has beendescribed as the glue thatbinds many different platformstogether with acommon interface. Thatis, a .NET object can talkto an EJB object withoutany problems. This is becauseWeb services provides a commoninterface and can be implementedusing any language. The data issent between the requestorand the receiver usingXML.Not to get into toomuch detail about Webservices, but here are somebasics. Simple Object AccessProtocol (SOAP) is used for exchangingdata between the client and the service.Web Services Description Language(WSDL) describes what services are availableand the method definitions withinthose services. WSDL supports ebXMLregistry features, which are similar toUDDIs. Universal Description, Discovery,and Integration has been organized as atype of directory lookup or yellow pagesfor Web services and is accessed via WSDL.Now you’re wondering, where doesEAServer 4.1 fit into this architecture?With 4.1 we support Web servicesnatively within the application server.The Web Services Toolkit generates aWSDL document and a client proxy. TheWSDL document describes the EAServercomponent you want to make availableas a Web service, as well as its location.Using the GUI, you can also publish thelocation of a WSDL document to a UDDIregistry on the Web.The Web Services Toolkit allows youto select a UDDI registry site and log in.After you log in, you can add businessand service data to it. Once you’ve publishedinformation to the registry, eachtime you log in the information isretrieved and available for you to review,modify, or delete.A business partner can use the clientproxy generated by the Web ServicesToolkit’s SOAP Management feature toinvoke a Web service without knowinghow to write SOAP messages. The clientproxy uses the WSDL document thatdescribes your Web service/EAServercomponent. The client application canthen use the Web service.Sybase makes it easy for their customersto create and distribute Web servicesfrom within EAServer.You’re Ready for the FutureWRITTEN BY TIM NESHAMWith the J2EE compatibility and theWeb services integration withinEAServer 4.1, you’re positioned for thefuture. EAServer 4.1 can provide theintegration between PowerBuilder, J2EE,and .NET. No other vendor can makethat statement.In the coming months look for morearticles on secure enterprise Web servicesand other Web services–enabledproducts from Sybase. ▼scott.mcreynolds@sybase.com26 PBDJ volume9 issue4www.SYS-CON.COM/pbdj/