Java Persistence API
Java Persistence API
object-relational mapping approach to bridge the gap between an object oriented model and a
relational database. Java Persistence consists of three areas:
existing naming and directory services such as LDAP, NDS, DNS, and NIS. It provides
applications with methods for performing standard directory operations, such as associating
attributes with objects and searching for objects using their attributes. Using JNDI, a Java EE
application can store and retrieve any type of named Java object, allowing Java EE applications
to coexist with many legacy applications and systems.
with access to a JNDI naming environment. A naming environment allows a component to be
customized without the need to access or change the component's source code. A container
implements the component's environment and provides it to the component as a JNDI naming
context.
component can create a javax.naming.InitialContext object and looks up the environment
naming context in InitialContext under the name java:comp/env. A component's naming
environment is stored directly in the environment naming context or in any of its direct or
indirect subcontexts.
of system-provided objects, such as JTA UserTransaction objects, are stored in the
environment naming context, java:comp/env. The Java EE platform allows a component to
name user-defined objects, such as enterprise beans, environment entries, JDBC DataSource
objects, and message connections. An object should be named within a subcontext of the
naming environment according to the type of the object. For example, enterprise beans are
named within the subcontext java:comp/env/ejb, and JDBC DataSource references in the
subcontext java:comp/env/jdbc.
application to authenticate and authorize a specific user or group of users to run it.