- Field-based Persistent Objects
EJB 3.0 supports a field-based relational model: each
Java field represents a database column. The tutorial
shows the configuration, classes, and client code for a single-table entity.
- 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. Transaction boundaries protect
database consistency by enforcing an all-or-none policy and using
the database's locking capabilities for scalability.
- 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. @OneToMany
represents a collection of children belonging to a parent,
like students in Gryffindor house at Hogwarts school.
- 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
- Persistent Sessions with Amber
HttpSessions combined with Amber improve the flexibility and performance
of persistent sessions.