Java™ Persistence API (JPA) is a new standard for data persistence in Web and distributed business applications. This standard replaces container-managed persistence (CMP) beans in the Java 2 Platform, Enterprise Edition (J2EE).
With extensible frameworks and tools, you can perform many tasks that are associated with accessing data for a multi-tier enterprise application:
With the JPA tools, you can generate JPA entities from existing database tables (bottom-up mapping) or database tables from existing JPA entities (top-down mapping).
Java Messaging Service (JMS) bindings can be used as a transport in addition to the Enterprise Information Server (EIS) bindings. You can use J2C properties editor to add and edit JMS bindings from the Service Component Architecture (SCA) component editor.
With the JPA tools, you can create the following types of mappings for JPA entities:
In order to minimize the complexity of mapping between JPA entities and tables, you can use wizards to create and automate initial mappings. You can also receive programming assistance from the tools through dynamic problem identification.
When you rename or move a class that is related to JPA, you can use a wizard to refactor all references to these classes in persistence.xml and orm.xml files.
You can work with JPA properties in either the JPA Details view or the Annotations view, so that you don’t need to keep both views open at once. For clarity, the Annotations view distinguishes between implied and specified annotation attributes.
By using Quick Fixes, that are available in the Java editor, you can easily add JPA support to a plain Java project. When you type a JPA annotation into a plain old Java object (POJO) in a plain Java project, the resulting compilation errors have Quick Fixes for adding the required JPA facet and an appropriate runtime environment (if available) to your project.