This chapter provides an overview of EIS projects and their components.
This chapter includes the following section:
For information on project concepts and features common to more than one type of TopLink projects, see Chapter 15, "Introduction to Projects".
Use an EIS project for transactional persistence of Java objects to a nonrelational data source accessed using a Java EE Connector Architecture (JCA) adapter and EIS records.
JCA 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 JCA 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.n connector.jar file from <ORACLE_HOME>/lib/java/api. 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 Section 5.2, "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 Chapter 18, "Introduction to 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 JCA 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 JCA, using the TopLink mappings described in Part XIX, "EIS Mappings".
You configure a TopLink EIS descriptor to use a particular EIS record format (see Section 76.4, "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 Section 5.6, "Using XML Schemas". For information on how TopLink supports XML namespaces, see Section 15.4, "XML Namespaces Overview".
Table 71-1 describes the components of an EIS project.
Table 71-1 EIS Project Components
| Component | Supported Types |
|---|---|
|
Data Source |
For more information, see the following: |
|
Descriptors |
For more information, see Section 74.1, "EIS Descriptor Concepts". |
|
Mappings |
For more information, see the following: |
You can create an EIS project with TopLink Workbench for use with EIS XML records (see Section 72.2, "Creating an EIS Project with XML Records") or you can build an EIS project in Java for use with any supported EIS record type (see Section 72.3, "Creating an EIS Project with Indexed or Mapped Records").
In an EIS project, your EIS interactions (see Section 108.9.3, "Enterprise Information System (EIS) Interactions") can make full use of TopLink queries (see Chapter 108, "Introduction to TopLink Queries"). However, you cannot use TopLink expressions with EIS: in an EIS project, interactions replace expressions.