1 EclipseLink DBWS Overview

This chapter introduces and describes EclipseLink DBWS which provides Jakarta EE-compliant, client-neutral access to relational database artifacts via a Web service. EclipseLink DBWS extends EclipseLink's core capabilities while leveraging its existing ORM and OXM components.

EclipseLink DBWS includes two parts

• A design-time component, the DBWSBuilder command-line utility, that generates the necessary deployment artifacts.

• A runtime provider component that takes a service descriptor (along with related deployment artifacts) and realizes it as a JAX-WS 2.0 Web service. The runtime provider uses EclipseLink to bridge between the database and the XML SOAP Messages used by Web service clients.

An EclipseLink DBWS service may include any number of the following operations:

1. insert – inserts into the database persistent entities described by an XML document.

2. update – updates database persistent entities described by an XML document.

3. delete – removes from the database persistent entities described by an XML document.

4. query – retrieves from the database persistent entities described by an XML document.

   Selection criteria for Query operations can be specified by:

   • custom SQL SELECT statement

   • Stored Procedure invocation

   • EclipseLink Named Query (that can use the complete range of EclipseLink ORM Expression Framework APIs)

   • JP-QL

The XML documents used by an operation conform to an XML Schema Definition (.xsd file).

This chapter includes the following sections:

• Understanding XML-to-Relational Mapping (XRM)

• Understanding the DBWS Builder File Properties

• Creating EclipseLink DBWS Services

• Using the DBWS Design Time Component