Download: Hibernate 3.0 Java Persistence

Hibernate 3.0, the latest persistence technology for Java, is available as an Open Source download. Get a rundown on the latest capabilities for data mapping between object, relational and even XML data resources, and a look into the future of EJB 3.0 architectures.

Tags: Hibernate, Support, Query, Mapping, SQL, Schema, XML,

The Hibernate 3.0 core is 68,549 lines of Java code together with 27,948 lines of unit tests, all freely available under the LGPL, and has been in development for well over a year.

Hibernate 3.0, a project run out of JBoss, the Open Source J2EE app server, is built to support a variety of data mapping technologies to make it easier for Java apps to interact with persistent data. It supports mapping for Object/Relational (O/R) assets, as well as XML, allows "a single definition of the transformation between various in-memory representations of the entity data and the relational schema," according to its project team. This functionality exists even with very complex legacy schemas and schemas for historical data or data with visibility rules.

Hibernate 3.0 also provides comprehensive object/relational query functionality, with three full-featured query facilities: Hibernate Query Language, the newly enhanced Hibernate Criteria Query API, and enhanced support for queries expressed in the native SQL dialect of the database. Among Hibernate 3.0's are:

  • Object/Relational/XML mapping: query XML directly from the database for reporting, replicate data between databases via intermediate XML, externalize entity data as XML when interacting with remote systems.
  • Support for exotic association and inheritance mappings, and greater flexibility when working with legacy data.
  • Filters for working with temporal (historical), regional or permissioned data.
  • Flexibility to mix hand-written and generated SQL within a single application or even a single entity:
  • Full support for "derived" entities and attributes defined in the mapping document, full support for overriding any generated SQL statement with handwritten SQL, support for stored procedures.
  • Enhanced ease of use: better defaulting, an unchecked exceptions model, simplified natural (and composite) key support, simplified CMT integration.
  • Enhanced Criteria query API: with full support for projection/aggregation and subselects.
  • Runtime performance monitoring: via JMX or local Java API, including a second-level cache browser; and
  • Eclipse support, including a suite of Eclipse plug-ins for working with Hibernate 3.0, including mapping editor, interactive query prototyping, schema reverse engineering tool.

    A full list of Hibernate 3.0 features is available: