Glossary

This glossary defines terms frequently used in this guide. For additional Java EE terminology, see http://java.sun.com/javaee/reference/glossary/index.jsp.

Annotation

A simple, expressive means of decorating Java source code with metadata that is compiled into the corresponding Java class files for interpretation at run time by a JPA persistence provider to manage JPA behavior. Annotations allow you to declaratively define how to map Java objects to relational database tables in a standard, portable way that works both inside a Java EE 5 application server and outside an EJB container in a Java Standard Edition (Java SE) 5 application. JPA annotations are specified in the javax.persistence package.

Entity

A Java object whose nontransient fields should be persisted to a relational database using the services of a JPA entity manager obtained from a JPA persistence provider (either within a Java EE EJB container or outside of an EJB container in a Java SE application). Using JPA, you can designate any POJO as an entity using the @Entity annotation.

Entity Manager

The interface that you use to access a persistence context. You use an entity manager to create, read, update, and delete entity instances.

J2CA

J2EE Connector Architecture: the standard way to integrate JMS providers with J2EE application servers by wrapping a JMS provider client library in a resource adapter.

JMS

Java Message Service.

JPA

The EJB 3.0 Java Persistence API.

OEMS

Oracle Enterprise Messaging Service: a suite of JMS providers that OC4J supports, including: OEMS JMS Connector (a J2CA-based provider), OEMS JMS (an in-memory or file-based provider), and OEMS JMS Database (Oracle AQ-based provider).

Oracle AQ

AQ is a unique database-integrated message queuing feature, built on the Oracle Streams information integration infrastructure. It allows diverse applications to communicate asynchronously through messages. Integration with the database provides unique message management functionality, such as auditing, tracking, and message persistence for security, scheduling, and message metadata analysis.

You can access AQ through PL/SQL, Java (using the oracle.AQ package), Java Message Service (JMS), or over the Internet using transport protocols such as HTTP, HTTPS, and SMTP. For Internet access, the client - a user or Internet application - and the Oracle server exchange structured XML messages.

AQ also provides transformations that are useful for enterprise application integration and a messaging gateway to automatically propagate messages to and from OracleAQ queues.

For more information, see http://otn.oracle.com/products/aq/index.html.

Persistence Context

The set of entity instances in which for any persistent entity identity there is a unique entity instance. A persistence context is associated with an entity manager instance. It is within this persistence context that the entity manager manages the entity instances and their life cycle.

Persistence Provider

An EJB 3.0 Java Persistence API implementation of

Persistence Unit

The set of entities that an entity manager instance manages. A persistence unit defines the set of all classes that are related by your application and which must be mapped to a single database.

POJI

Plain Old Java Interface: an interface that you define; one that need not extend an interface that Java EE specifies. In EJB 3.0, a business interface may be a POJI.

POJO

Plain Old Java Object: a Java class that you define; one that need not extend a class or implement an interface that Java EE specifies. In EJB 3.0, an entity may be a POJO.

RA

Resource Adapter: specifically, one that complies with J2CA.