Amber aims at relational database persistence with an application-oriented data model.

The Amber bean lifecycle follows the JDO 1.0 model. Amber supports both transactional and non-transactional lifecycles.

Field-based Persistent Objects

EJB 3.0 supports a field-based relational model: each Java field represents a database column.

Property-based Persistent Object

Basic CMP example showing configuration, classes, and client code for a single-table bean.

Creating and Removing Entity Beans

Describes the basic create/remove api for entity beans.

Transaction Method Annotations

Transaction annotations make reliable database updates clear, straightforward and scalable.

Query CMP

The EJB 3.0 Query API resembles the JDBC PreparedStatement with enhanced SQL and direct support for objects.0.

Links: The @ManyToOne Relation

The Many-to-One link is the foundation of persistent relations. It links a source table to a destination with a database REFERENCES column. Many-to-One adds two capabilities: SQL extensions for links and direct lookup of target beans through field references.

Collections: The @OneToMany Relation

The @OneToMany relation adds collection extensions to the query language and provides a Java Collection containing the children.

Many-to-Many CMP

Illustrates using many-to-many relations of EJB 3.0.

CMP Inheritance

EJB 3.0 supports database-backed inheritance, allowing for persistent-backed polymorphism and more sophisticated object-oriented modelling.

Persistent Sessions with Amber

HttpSessions combined with Amber improve the flexibility and performance of persistent sessions.