JEE Core Concepts: Difference between revisions

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=Subjects=
=Subjects=


* [[JEE Core Concepts -
* [[JEE Core Concepts - Resources, Naming and Injection|JEE Resources, Naming and Injection]]
 
* [[JCA Concepts]]
=Resources, Naming and Injection=
* [[EJB Concepts]]
 
* [[JPA Concepts]]
 
 
Changing Application Behavior without Changing Code
 
The possibility to change an application's behavior without changing code is a core concern in JEE. The entire Chapter 5 in the [[JEE#jsr_316|JEE specifications]] is dedicated to it.
 
The essential mechanism than makes this possible is the ''application component environment'', also known as ''enterprise naming context'' or ''ENC''. ENC is a JNDI naming context, accessible to and private for each application component.
 
The application code uses ENC ''named entries'' to refer to configuration values and external resources. The names of those elements do not change in the code, and those names are mapped to deployment environment specific values and resources during deployment. The use of ''deployment descriptors'' is essential part of the mapping. The deployment descriptors act as a layer of indirection between code and the deployment environment, and provide the mappings mentioned above. The code does not change, but the deployment descriptors do.
 
==Application Component Environment==
 
==Environment Entry==
 
===Simple Environment Entry===
 
=TODO=
 
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* Review [[WildFly JNDI Concepts]].
* Review [[@javax.annotation.Resource]]
* Review [[EJB_Annotations#.40javax.ejb.EJB]]
* Try to bind entries in jboss-app.xml, jboss-web.xml, etc.
 
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Latest revision as of 13:21, 25 September 2017

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