EIS Projects

Use an EIS project for transactional persistence of Java objects to a nonrelational data source accessed using a J2EE Connector Architecture (J2C) adapter and EIS records.

J2C provides a Common Client Interface (CCI) API to access nonrelational EIS. This provides a similar interface to nonrelational data sources as JDBC provides for relational data sources. This API defines several types of nonrelational record types including mapped and indexed. XML has emerged as the standard format to exchange data, and most leading J2C adapter providers have extended the CCI API to define XML data records.

To use a JCA adapter with TopLink EIS, the JCA adapter must support the JCA CCI interface. At run time, your JCA adapter and the Java connector.jar file (that contains the javax.resource.cci and javax.resource.spi interfaces that TopLink EIS uses) must be on your application or application server classpath.

If you are using TopLink Workbench, you must add your JCA adapter to the TopLink Workbench classpath. By default, TopLink Workbench updates its classpath to include the Java 1.5 connector.jar file from <TOPLINK_HOME>/j2ee/home/lib. If this version of the connector.jar file is incompatible with your environment, edit the workbench.cmd or workbench.sh file in <TOPLINK_HOME>/bin to change the path to this file. For more information, see "Configuring the TopLink Workbench Environment".

EIS includes legacy data sources, enterprise applications, legacy applications, and other information systems. These systems include such sources as Custormer Information Control System (CICS), Virtual Storage Access Method (VSAM), Information Management System (IMS), ADABASE database, and flat files.

Oracle recommends using EIS projects to integrate TopLink with a legacy or nonrelational data source. Other methods of accessing EIS data sources include:

Using a specialized JDBC driver that allows connecting to an EIS system as if it were a relational database. You could use a TopLink relational project with these drivers (see "Relational Projects").
Linking to or integrating with the EIS data from a relational database, such as Oracle Database.
Using a proprietary API to access the EIS system. In this case it may be possible to wrap the API with a J2C CCI interface to allow usage with a TopLink EIS project.

TopLink provides support for mapping Java objects to EIS mapped, indexed, and XML records, through J2C, using the TopLink mappings described in Part XIII, "EIS Mappings".

You configure a TopLink EIS descriptor to use a particular EIS record format (see "Configuring Record Format"). TopLink EIS mappings use their EIS descriptor's record format configuration to determine how to map their Java objects to EIS records.

If you use XML records, the TopLink runtime performs XML data conversion based on one or more XML schemas. In an EIS project that uses XML records, TopLink Workbench directly references schemas in the deployment XML, and exports mappings configured with respect to the schemas you specify. For information on how to use TopLink Workbench with XML schemas, see "Working With XML Schemas". For information on how TopLink supports XML namespaces, see "XML Namespaces".

Table 20-5 describes the components of an EIS project.

Table 20-5 EIS Project Components

Component	Supported Types
Data Source	For more information, see the following: "EISLogin" "EIS Platforms"
Descriptors	For more information, see "EIS Descriptors".
Mappings	For more information, see the following: Part X, "Mappings" Part XIII, "EIS Mappings"

Component

Supported Types

Data Source

For more information, see the following:

Descriptors

For more information, see "EIS Descriptors".

Mappings

For more information, see the following:

You can create an EIS project with TopLink Workbench for use with EIS XML records (see "Building EIS Projects with XML Records") or you can build an EIS project in Java for use with any supported EIS record type (see "Building EIS Projects With Indexed or Mapped Records").

In an EIS project, your EIS interactions (see "Enterprise Information System (EIS) Interactions") can make full use of TopLink queries (see "Understanding TopLink Queries"). However, you cannot use TopLink expressions with EIS: in an EIS project, interactions replace expressions.

Building EIS Projects with XML Records

TopLink Workbench provides complete support for creating EIS projects that map Java objects to EIS XML records.

Using TopLink Workbench, you can create an EIS project for transactional persistence of Java objects to a non-relational data source accessed using a J2C adapter and EIS XML records.

The TopLink runtime performs XML data conversions based on one or more XML schemas. In an EIS project, TopLink Workbench does not directly reference schemas in the deployment XML, but instead exports mappings configured in accordance to specific schemas.

EIS queries use XMLInteraction. For more information, see "Using EIS Interactions".

Building EIS Projects With Indexed or Mapped Records

TopLink Workbench does not currently support non-XML EIS projects. You must create such an EIS project in Java.

Using Java, you can create an EIS project for transactional persistence of Java objects to a nonrelational data source accessed using a J2C adapter and any supported EIS record type including indexed, mapped, or XML records.

If you use XML records, the TopLink runtime performs XML data conversion based on one or more XML schemas. When you create an EIS project in Java, you configure mappings with respect to these schemas, but the TopLink runtime does not directly reference them.

You can base queries on any supported EIS interaction: IndexedInteraction, MappedInteraction (including QueryStringInteraction), or XMLInteraction (including XQueryInteraction). For more information, see "Using EIS Interactions".