5.6 Web services support

XML and its associated family of standards play a central role in Web services by providing a data interchange format that is independent of both programming languages and operating systems. This section gives an overview of the support provided by the Application Developer for XML-based Web services. For detailed information about the development of XML Web services using Websphere Studio Application Developer, please refer to Chapter 9. Please note that we assume you already have a background about Web services.

To start developing your Web service, you will need to create a Web project in your work space to contain the Web service. To implement your XML Web service, the Application Developer provides you with the two very important wizards to use.

Web Service DADX group configuration wizard

DAD extension (DADX) is an extension of the DB2 XML Extender document access definition (DAD) file. A DADX document specifies how to create a Web service using a set of operations that are defined by SQL statements or DAD files. DAD files are files that describe the mapping between XML documents elements and DB2 database columns. They are used by the DB2 XML Extender, which supports XML-based operations that store or retrieve XML documents to and from DB2 database.

The Web services DADX group configuration wizard enables you to create a DADX group. The DADX group created with this wizard is used to store DADX documents. A DADX group contains connection (JDBC and JNDI) and other information that is shared between DADX files.

Once you have created a DADX group, you can import DADX files and then start the Web services wizard to create a Web service from a DADX file. A DADX file is created using the XML from SQL query wizard.

Web service wizard

This wizard is used for creating Web services. It is cable of generating several types of Web services. The focus of this book is only on DADX Web services. Using the wizard, you can specify to generate a Web service proxy class. A Web service proxy class makes it very easy to invoke a Web service. You just instantiate the class and invoke the desired method on it.

Moreover, the wizard gives you the ability to generate and invoke a sample application. The sample application is a small Web application, which enables you to invoke the different methods of the Web service, and to view the results.

98 The XML Files: Development of XML/XSL Applications Using WebSphere Studio

Page 114
Image 114
IBM Version 5 manual Web services support, Web Service Dadx group configuration wizard, Web service wizard