web server - Borland Technical Publications

Chapter
15
15Entity Beans and Table Mapping for
Chapter
CMP 2.0
Important
Here we'll examine how entity beans are deployed in the Borland Enterprise Server
and how persistence of entities can be managed. This is not, however, an introduction
to entity beans and should not be treated as such. Rather, this document will explore
the implications of using entity beans within Borland Partitions. We'll discuss descriptor
information, persistence options, and other container-optimizations. Information on the
Borland-specific deployment descriptors and implementations of Container-Managed
Persistence (CMP) will be documented in favor of general EJB information that is
generally available from the J2EE Specifications from Sun Microsystems.
For documentation updates, go to www.borland.com/techpubs/bes.
Entity Beans
Entity beans represent a view of data stored in a database. Entity beans can be finegrained
entities mapping to a single table with a one-to-one correspondence between
entity beans and table rows. Or, entity beans can span multiple tables and present data
independent of the underlying database schema. Entity beans can have relationships
with one another, can be queried for data by clients, and can be shared among
different clients.
Deploying your Entity Bean to one of the Borland Enterprise Server Partitions requires
that it be packaged as a part of a JAR. The JAR must include two descriptor files: ejbjar.xml
and the proprietary ejb-borland.xml file. The ejb-jar.xml descriptor is fullydocumented
in the J2EE 1.3 Specification. The DTD for ejb-borland.xml is reproduced
in this document and aspects of its usage documented here. The Borland proprietary
descriptor allows for the configuration of a number of properties that can be set to
optimize container performance and manage the persistence of your entity beans.
Chapter 15: Entity Beans and Table Mapping for CMP 2.0 127