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<html xmlns="http://www.w3.org/1999/xhtml"><head><title>Enterprise JavaBeans and POJO-Based Enterprise Frameworks</title><link rel="stylesheet" href="core.css" type="text/css"/><meta name="generator" content="DocBook XSL Stylesheets V1.74.0"/></head><body><div class="sect1" title="Enterprise JavaBeans and POJO-Based Enterprise Frameworks"><div class="titlepage"><div><div><h1 class="title"><a id="learnjava3-CHP-22-SECT-13"/>Enterprise JavaBeans and POJO-Based Enterprise Frameworks</h1></div></div></div><p><a id="idx11144" class="indexterm"/> <a id="idx11145" class="indexterm"/> <a id="idx11154" class="indexterm"/> <a id="idx11163" class="indexterm"/> <a id="idx11170" class="indexterm"/> <a id="idx11171" class="indexterm"/> <a id="I_indexterm22_id824636" class="indexterm"/>Enterprise JavaBeans (EJB) is a very big topic, and we can’t
do more than provide a few paragraphs of insight here. If you want more
information, see <a class="ulink" href="http://shop.oreilly.com/product/9780596158033.do"><span class="emphasis"><em>Enterprise
JavaBeans</em></span></a> by Richard Monson-Haefel (O’Reilly). The
thrust of EJB takes the JavaBeans philosophy of portable, pluggable
components and extends it to the server side to accommodate the sorts of
things that multitiered, networked, and database-centric applications
require. Although EJB pays homage to the basic JavaBeans concepts, it is
much larger and more specialized. It doesn’t have a lot in common with the
kinds of things we’ve been talking about in this chapter. EJBs are
server-side components for networked applications. EJBs and plain Java
beans are both reusable, portable components that can be deployed and
configured for specific environments. But in the case of EJBs, the
components encapsulate access to business logic and database tables
instead of GUI and program elements.</p><p>EJB ties together a number of other Java enterprise-oriented
APIs—including database access, transactions, and name services—into a
single component model for server applications. EJB imposes a lot more
structure on how you write code than plain-old Java beans. It does so to
allow the server-side <span class="emphasis"><em>EJB container</em></span> to take on a lot
of responsibility and optimize your application’s activities without your
having to write a lot of code.</p><p>The first two major releases of <em class="firstterm">Java Enterprise
Edition</em>, which include EJBs, were considered by many to be
overly complicated. Many classes, interfaces, and configuration files were
required to support EJBs. As a result, a number of popular open source
frameworks that make use of Plain Old Java Objects (POJOs) to accomplish
the same tasks quickly rose to prominence. POJOs are Java objects that are
not required to follow any convention, implement any interface, or inherit
from any base class, although in practice they are often JavaBeans. The
most notable of the POJO-based frameworks are Hibernate, a framework for
mapping Java object state to a database, and Spring, a general-purpose
enterprise application development framework.<a id="I_indexterm22_id824694" class="indexterm"/><a id="I_indexterm22_id824702" class="indexterm"/><a id="I_indexterm22_id824709" class="indexterm"/><a id="I_indexterm22_id824716" class="indexterm"/><a id="I_indexterm22_id824723" class="indexterm"/><a id="I_indexterm22_id824730" class="indexterm"/></p></div></body></html>