WebSphere Developer for System z IBM-CICS

WebSphere Developer for System z is based on the IBM Rational® Software Development Platform and facilitates the development of both Java and z/OS-based applications. It includes capabilities that make traditional z/OS mainframe development, Web development, and integrated composite development faster and more efficient.

Of particular interest to this book, WebSphere Developer for System z (WD/z) contains tools that support the development of Web services and the XML enablement of new and existing CICS COBOL and C/C++ applications. We describe some of the features and the use of WD/z that assisted us in the development, testing, and deployment of our sample application.

1. Introducing WebSphere Developer for System z

WebSphere Developer for System z V7.0 comprises an interactive workstation-based environment and an integrated set of tools to help create, maintain, and re-use applications for traditional processing or inclusion in an SOA. It consists of a common workbench that supports end-to-end, model-based development, run-time testing, and rapid deployment of simple and complex applications.

Following are some of the main features of WD/z:

  • Accelerates the development of Web applications, traditional COBOL and PL/I applications, Web services, XML-based interfaces, and high-level Enterprise Generation Language
  • Includes significant enhancements that increase efficiency of traditional mainframe, Web development, and services
  • Promotes the re-use and transformation of existing applications to help reduce costs and shorten the development cycle
  • Facilitates mainframe application development, Web development, and integrated mixed workload or composite development faster and more efficient
  • Enables business service integration for CICS applications
  • Consists of workbench and integrated tools that support model-based application development, runtime testing, and rapid deployment
  • Provides an interactive, workstation-based environment with convenient and consistent access to IBM z/OS datasets, HFS, and JES Spool files

2. The Eclipse platform

WebSphere Developer for System z is a product based on the Eclipse platform. The Eclipse platform is a GUI toolkit and plug-in architecture for building rich client applications. It is defined at www.eclipse.org as follows:

“Eclipse is an open source community whose projects are focused on building an open development platform comprised of extensible frameworks, tools and runtimes for building, deploying and managing software across the lifecycle.”

Eclipse overview

The Eclipse platform incorporates the concept of a “work space” that maintains everything needed by the developer for building and testing a project. The work space is locally maintained on a developer’s own workstation, containing the configuration settings of tools, plug-ins, the data objects being edited, and the intermediate and complete form of the components being developed.

The use of a local work space allows for very efficient team collaboration through repositories that can be Internet, rather than LAN, accessible.

Eclipse architecture

The Eclipse platform is a framework with a powerful set of services structured as subsystems that are implemented in one or more plug-ins. Following are the subsystems, or major components, that make up the framework:

  • Platform runtime
  • Work space
  • Workbench
  • Team support
  • Help

Figure shows a simplified view of the major components.

The Eclipse platform componentsThe Eclipse platform components

The Eclipse platform components

  • Platform

The platform run time is the kernel that discovers at start-up what plug-ins are installed and creates a registry of information about them. To reduce start-up time and resource usage, it does not load any plug-in until it is actually needed. Except for the kernel, everything else is implemented as a plug-in.

  • Work space

The work space is the plug-in responsible for managing the user's resources. This includes the projects the user creates, the files in those projects, and changes to files and other resources. The work space is also responsible for notifying other interested plug-ins about resource changes, such as files that are created, deleted, or changed.

  • Workbench

The workbench provides Eclipse with a user interface. It is built using the Standard Widget Toolkit (SWT)—a nonstandard alternative to Java's Swing/AWT GUI API—and a higher-level API, JFace, built on top of SWT that provides user interface components including file buffers, text handling, and text editors.

  • Team support

The team support component provides support for version control and configuration management. It adds views as necessary to allow the user to interact with what ever version control system (if any) is being used. Most plug-ins do not need to interact with the team support component unless they provide version control services.

  • Help

The help component parallels the extensibility of the Eclipse Platform itself. In the same way that plug-ins add functionality to Eclipse, help provides an add-on navigation structure that allows tools to add documentation in the form of HTML files.

3. The WebSphere Developer for System z Workbench

The term workbench refers to the desktop development environment. The workbench aims to achieve seamless tool integration and controlled openness by providing a common paradigm for the creation, management, and navigation of work space resources.

The user interfaces are based on editors, views, and perspectives. From a user’s standpoint, a workbench window visually consists of several views and editors. Perspectives manifest themselves in the selection and arrangements of editors and views visible on the window. More than one workbench window usually shows on the desktop at any given time.

Editors allow the user to open, edit, and save objects and files. Views provide information about some object that the user is working within the workbench. A view may assist an editor by providing information about the document being edited.

When you first start up WD/z, a Welcome window appears, as in Figure below. There are tutorials, samples, and overviews that are accessible from this window, which we highly recommend for first-time users to become familiar with the tooling.

To go to the workbench, click the highlighted icon, as shown in Figure.

The WD/z Welcome window with Workbench selection

The WD/z Welcome window with Workbench selection

In WD/z, the default workbench comprises the z/OS Projects Perspective. Notice that the current perspective is set to z/OS Projects in the top-right of the workbench.

To change perspectives, there is a drop down selection icon to the left of the current perspective name. Alternatively, you can use Window → Open Perspective to select a different set of views that pertain to the type of development task you are performing.

The z/OS Projects (default) Workbench

The z/OS Projects (default) Workbench

With reference to Figure , there are a number of views or panes that are now displayed.

The Navigator view in this perspective is labeled z/OS Projects, and it provides an Explorer-type view of projects and their members, which can be selected for edit, create, and delete. The greyed out panel to the right of the Navigator is the Editor area. Depending on the type of document selected in the Navigator, an appropriate editor window opens here, using a plug-in provided with the product. If an appropriate editor registered for a particular document type is not found (for example, a .doc file on a Windows® system), Eclipse will try to open the document using an external editor.

The Outline and the Properties views below the Navigator, present an outline of the document currently selected in the editor and the properties that are attributed to the file or document. The precise nature of these views depends on the editor and the type of document. For a Java source file, for example, the outline displays any declared classes, attributes, and methods.

The Remote Systems view allows connections to be made to Remote hosts and then provides an explorer view of the resources on the host. In WD/z, connections can be made to either AIX® or z/OS host systems.

4. z/OS application development tools in WD/z

z/OS application development tools provide an interactive, workstation-based environment where you can develop mainframe applications in Assembler, COBOL, C/C++ or PL/I. The environment gives you an interactive way to edit on the workstation and prepare output on the mainframe. Interaction with z/OS allows you to do the following:

  • Create or modify the code in the z/OS LPEX editor. The editor maintains fixed length records, sequence numbers, and file locking (ISPF ENQ/DEQ) as appropriate.
  • Validate the source using the syntax check function.
  • Debug the code.
  • Generate and customize JCL as needed.

You can access z/OS data sets by way of a workstation-like directory structure, and you can process CLISTs and REXX™ EXECs in the following way:

  1. Edit them on the workstation.
  2. Transfer them to z/OS.

5. Web services development scenarios

WebSphere Developer for System z provides the development framework for major Web service enablement scenarios that are typical for a service-oriented architecture (SOA). The functionality comes with the Enterprise Service Tools (EST) in WD/z, which assist in creating enterprise applications that fit the established patterns of Web services enablement.

Following are the major Web services enablement scenarios that are typical for a service-oriented architecture:

  • Bottom-up development
  • Meet-in-the-middle development
  • Top-down development

The scenarios are described in the following two contexts:

  1. The creation of a Web service that invokes a single application. This context is applicable to most types of Enterprise Service Tools projects.
  2. The creation of a comprehensive Web service capable of collecting and processing data from multiple CICS applications or from other Web services.

This context is applicable to service flow projects.

Bottom-up development

This approach generates a Web service description and run-time specific inbound and outbound XML message processing from a high-level data structure. You can use this method to create a Web service provider program for an existing CICS application.

Meet-in-the-middle development

This defines mappings between high level data structures and WSDL, XML, or XSD files. You can use this method to generate run-time specific inbound and outbound XML message processing based on the mappings.

Top-down development

This generates a high-level language structure and run-time specific inbound and outbound XML message processing from a Web service description WSDL file.

You can use this method to do the following:

  • Create a Web service provider program (one that runs using Web services for CICS protocols) for a new application.
  • Create a Web service provider program (one that runs using Web services for CICS protocols) for an existing application.
  • Create a Web service requester program (one that runs using Web services for CICS protocols).

6.Enterprise Service Tools

Enterprise Service Tools (EST) is an integrated perspective that assists a CICS developer in the following tasks:

  • Creating a CICS Web service that uses a new or existing CICS application as its application component.
  • Creating a SOAP-enabled CICS Web service that uses a new or existing CICS application as its application component.
  • Creating an IMS SOAP Gateway Web service that uses a new or existing IMS application as its application component.
  • Creating a Web service that is not run-time specific from a new or existing application.
  • Using the System z Database Application Generator to create a COBOL CICS application that accesses a Z/OS DB2 database.
  • Developing a comprehensive Web service that collects and processes data from multiple sources, including CICS non-terminal applications, CICS terminal applications, and Web services.

Enterprise Service Tools combine capabilities that were formerly available in the XML Services for the Enterprise plug-in and the Service Flow Modeller plug-in. EST features an enhanced user interface that increases usability and simplifies the overall service and flow development process.

Artifacts generated by WD/z Web Services wizard

Artifacts generated by WD/z Web Services wizard

Following are the artifacts generated by the Web Services Enablement wizard:

  • Input converter

A COBOL program that takes an incoming XML document and maps it into the corresponding COBOL data structure that the existing CICS application expects.

  • Output converter

A COBOL program that takes the COBOL data results returned from the CICS application and maps them to an XML document.

  • Converter driver

A COBOL program that shows how the input and output converters can be used to interact with the existing CICS application.

  • Input document XML schema definition (XSD)

XML schema that describes the incoming XML document.

  • Output document XML schema definition (XSD)

XML schema that describes the outgoing XML document.

  • WSDL

Web service description file.

  • WSBind

Web service binding file.



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