docs/org.eclipse.jst.ejb.doc.user/topics/cejb3.dita

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<concept id="cejb3" xml:lang="en-us">
<title>Developing EJB 3.1 Applications</title>
<shortdesc>You can use the workbench to develop and test enterprise
beans that conform to the distributed component architecture defined
in the Sun Microsystems Enterprise JavaBeans (EJB) 3.10 specification.</shortdesc>
<prolog><metadata>
<keywords><indexterm>Enterprise JavaBeans 3.0</indexterm></keywords>
</metadata></prolog>
<conbody>
<p> Using this specification, you can develop beans more simply than
in the 2.1 standard. You can annotate your Java source code to provide
information that was previously contained in XML deployment descriptors.
Using <tm tmclass="special" tmowner="Sun Microsystems, Inc." tmtype="tm"
trademark="Java">Java</tm> annotations allows you to create EJBs and <tm
tmclass="special" tmowner="Sun Microsystems, Inc." tmtype="tm"
trademark="Java">Java</tm> Persistence Architecture (JPA) beans quickly
and easily from “plain old <tm tmclass="special"
tmowner="Sun Microsystems, Inc." tmtype="tm" trademark="Java">Java</tm> objects
(POJOs).  For EJBs, these can be created without implementing EnterpriseBean
interfaces. </p>
<p>This product supports the Enterprise JavaBeans 2.1 and 3.0 specification
levels.  All of the EJB tools in the product are accessible from the <tm
tmclass="special" tmowner="Sun Microsystems, Inc." tmtype="tm"
trademark="Java">Java</tm> EE perspective in the workbench. You can
create session beans (stateful or stateless) or message-driven beans,
by simply specifying the component defining annotation in your POJO.
 Additional configuration for your bean can be done by specifying
additional annotations in the <tm tmclass="special"
tmowner="Sun Microsystems, Inc." tmtype="tm" trademark="Java">Java</tm> class.
The <tm tmclass="special" tmowner="Sun Microsystems, Inc." tmtype="tm"
trademark="Java">Java</tm> editor provides validation, content assistance
and QuickFixes for your EJB 3.0 annotations, as well as support for
refactoring beans. For richer assistance with the EJB 3.0 annotations,
you can use the Annotations view to add or delete annotations, and
to modify the attribute values of annotations. Deployment descriptors
for your EJB 3.0 modules are optional, but can be created for additional
configuration.</p>
<p><b>New in EJB 3.1 (JSR 318)</b></p>
<p><ul>
<li>Singleton beans (@Singleton)<ul>
<li>Before EJB 3.1, there was no easy way to share data throughout
the application; the EJB 3.1 Singleton is an application-wide singleton.</li>
<li> Concurrency can be managed either by the container or by the
Bean Developer</li>
</ul></li>
</ul></p>
<p>Java EE 5 streamlines EJB development in the following ways: <ul>
<li>Fewer required classes and interfaces<ul>
<li>Home and object interfaces are no longer required – you need the
business interface only</li>
<li>No need to implement javax.ejb.SessionBean</li>
<li>No need to declare checked exceptions</li>
</ul></li>
<li>Optional deployment descriptors<ul>
<li>Annotations provide component definition and dependency injection</li>
</ul></li>
<li>Simple lookups<ul>
<li>new EJBContext() interface method replaces JNDI calls</li>
</ul></li>
<li>Lightweight persistence for object-relational mapping<ul>
<li>Entities are POJOs that provide an object-oriented view of the
data stored in relational database</li>
</ul></li>
<li>New Interceptors class (new in Java EE 5)<ul>
<li>Interceptors are objects that can intercept a call to a business
method (to handle security for example)</li>
<li>Similar in purpose and action to servlet filter or Web services
handler</li>
<li>Provide limited form of aspect-oriented programming</li>
</ul></li>
</ul></p><?Pub Caret -2?>
<p>For further additional information on EJB 3.0, see the official
specification: <xref href="http://jcp.org/en/jsr/detail?id=220"
scope="external">JSR 220: Enterprise <tm tmclass="special"
tmowner="Sun Microsystems, Inc." tmtype="tm" trademark="JavaBeans">JavaBeans</tm> 3.0 </xref></p>
</conbody>
</concept>
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