TopLink

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TopLink

Developed by	Oracle Corporation
Latest release	10g
Preview release	11g preview / May 10, 2007
Written in	Java
OS	Cross-platform
Platform	Java Virtual Machine
Genre	Object-relational mapping
License	Oracle Licence
Website	http://www.oracle.com/technology/products/ias/toplink/

TopLink is an object-relational mapping package for Java developers. It provides a powerful and flexible framework for storing Java objects in a relational database or for converting Java objects to XML documents.

TopLink Essentials [1] is the Reference implementation of the EJB 3.0 Java Persistence API (JPA) and the open-source community edition of Oracle's TopLink product. TopLink Essentials is a limited version of the proprietary product. For example, TopLink Essentials doesn't provide cache synchronization between clustered application, some cache invalidation policy, and query Cache.

[edit] History

TopLink was originally developed by The Object People in Smalltalk in the 1990s. The "TOP" in TopLink is an acronym for The Object People, and the name was originally capitalized as "TOPLink". In 1996-1998 a Java version of the product was added to the product line, named TopLink for Java. After the joint acquisition of The Object People in April 2000 by BEA Systems and WebGain, TopLink product line became the property of WebGain.

In 2002, TopLink was acquired by Oracle Corporation and continues to be developed as a member of the Oracle Fusion Middleware family of products.

In 2006, Oracle donated source code from the TopLink product and development resources to the open source Sun Microsystems java.net Glassfish project. This project was named TopLink Essentials and was the Java EE EJB 3.0 JPA reference implementation.

In 2007, Oracle donated the source code from the TopLink product and development resources to the open source Eclipse Foundation EclipseLink project[2].

In March 2008, The Eclipse Foundation, announced [3] that Sun Microsystems has selected the EclipseLink project as the reference implementation for the JPA 2.0, JSR 317 standard to succeed TopLink Essentials.

More details on TopLink's history here: History of TopLink.

TopLink continues to be a major player in its field, winning multiple awards including:

Voted as the 4th best Java persistence architecture by Java Developer's Journal readers (2004)
Editor's Choice JavaWorld 2003 Award for Best Java Data Access Tool (2003)
Java Pro Readers' Choice Award for Best Java Data Access Tool or Driver (July 2003)

[edit] Features

Although widely known as an object-relational mapping tool, TopLink has a number of other key features including:

Rich query framework that supports an object-oriented expression framework, Query by Example (QBE), EJB QL, SQL, and stored procedures
An object-level transaction framework
Advanced caching to ensure object identity
Complete set of direct and relational mappings
Object-to-XML mappings, in addition to JAXB support
EIS/JCA Support for non-relational datasources
Visual mapping editor (Mapping Workbench)
Limited support for query in memory