The J2EE specification attempts to fill the gaps between the web components and Enterprise JavaBeans by defining how these technologies come together to form a complete platform.
One of the ways in which J2EE adds value is by creating a consistent
programming model across web components and enterprise beans through
the use of the JNDI ENC and XML deployment descriptors. A servlet in
J2EE can access JDBC
environment entries, and references to enterprise beans through a
JNDI ENC in exactly the same way that enterprise beans use the JNDI
ENC. To support the JNDI ENC, web components have their own XML
deployment descriptor that declares elements for the JNDI ENC
<env-entry>) as well security roles and
other elements specific to web components. In J2EE, web components
are packaged along with their XML deployment descriptors and deployed
in JAR files with the extension
stands for web archive. The
use of the JNDI ENC, deployment descriptors, and JAR files in web
components makes them consistent with the EJB programming model and
unifies the entire J2EE platform.
Use of the JNDI ENC makes it much simpler for web components to
access Enterprise JavaBeans. The web component developer does not
need to be concerned with the network location of enterprise beans;
the server will map the
listed in the deployment descriptor to the enterprise beans at
Optionally, J2EE vendors can ...