Doron Sherman

In my last article (WSDJ, Vol. 1, issue 4) I showed you how to use WebSphere Studio Application Developer (WSAD) to develop and publish a Web service. You saw how to use the Web services wizard to wrap an existing Java method as a Web service and expose the metadata required for invoking the service. You also saw how the UDDI Explorer is used to publish your service on a public registry so others can find and use it. This month's focus is on discovering the service and building a client that invokes the Web service. You'll learn more about how WSAD hides the complexity and mechanics of Web services by introducing a set of tools and wizards. You can do all your Web services development quickly and efficiently, without writing a single line of XML. Last time I focused on the Web service developer (and publisher); this month I focus on the consumer - the developer of th... (more)

BPEL: Make Your Services Flow

Until now, the options available for implementing business flows in a typical enterprise-computing environment were daunting. IT project managers had to choose between complex high-end EAI/BPM solutions and high-risk application development projects. More often than not, IT decision makers opted to do nothing and wait. When IBM, Microsoft, and others submitted the BPEL4WS specification to OASIS, a compelling alternative to the traditional options became available. BPEL is to process orchestration what SQL was to data management. Its impact is significant; transforming applicatio... (more)

XML Computation Trees

Every computer science undergraduate program in the world has two important foundation courses: data structures and algorithms. Open any book on these subjects and you'll see immediately that almost a third of it is devoted to graphs. Graphs are used to model a very large number of real-world problems: the traveling salesman problem, efficient routing of a package, network flows, and more - all are modeled as graphs and often solved by graph-based algorithms. A common use of a graph-based representation is that of a computation graph. Simply put, it's a graph that models a set o... (more)

Delivering SOA

With the rapid adoption of Web services standards and increasing support for asynchronous and XML-based messaging in the J2EE specification (JMS, MDB, JAXM, JAXRPC), it's time to address the challenges involved in building business applications based on a service-oriented architecture. This evolution impacts current practices for Web application development, which now need to support this new paradigm. It also presents challenges for application deployment and management, commonly addressed today through proprietary enterprise application integration (EAI) solutions. In essence, ... (more)

Building DB2-Based Web Services Using WebSphere, Part 2

In my previous article (WSDJ, Vol. 1, issue 7), I gave you a glimpse of the Web Services Object Runtime Framework (WORF), a set of tools for implementing Web services with DB2 and WebSphere. WORF is deployed on WebSphere Application Server (WAS) and uses Apache SOAP 2.2. It implements a layer that runs on WAS and is responsible for taking database access definitions and translating them on-the-fly to Web services constructs supporting SOAP messages and WSDL documents. The mapping between the database definitions and the Web service is done in a Document Access Definition eXtensi... (more)