About J2EE Archive Formats

A J2EE archive file contains a J2EE module or application. A module consists of one or more packaged JDeveloper projects of a common component type. An application is comprised of one or more modules. An archive also contains a deployment descriptor, which is an XML file that describes the configuration of the module or application to the server, and is specific to the type of the server.

The following table lists the archive types and their associated module types and contents, as supported by JDeveloper:

Archive Type	Module Type	Software Content	Deployment Descriptors
Java Archive (JAR)	J2EE client module	Java Application components	`application-client.xml` `orion-application-client.xml`
EJB JAR	J2EE EJB module	Enterprise JavaBeans (EJB) components	`ejb-jar.xml orion-ejb-jar.xml weblogic-ejb-jar.xml jboss.xml`
Web Archive (WAR)	J2EE web module	Servlets and JavaServer Pages (JSP) components	`web.xml` `orion-web.xml` `weblogic.xml`
Enterprise Archive (EAR)	n/a	J2EE Enterprise Application	`application.xml` `orion-application.xml`

JAR, EJB JAR, and WAR files each contain a module consisting of one or more components. An Enterprise Archive (EAR file) contains an application consisting of one or more packaged modules. According to the J2EE specification, every application must be assembled and packaged as an EAR file prior to deployment to a J2EE server.

When you create a web (servlet or JSP) or EJB application and deploy it via an application server connection, JDeveloper packages it as a WAR or EJB JAR wrapped in an EAR file. If your application consists of components of differing types, the components will be packaged into multiple modules, and you must create an EAR deployment profile to assemble them as an EAR file.

For more information about about J2EE archive formats, see these references:

The "J2EE Blueprints" is an integrated set of documentation and example applications that illustrate best practices for developing J2EE compatible applications. Refer to the "Packaging and Deployment" chapter. You can download a copy from http://java.sun.com/j2ee/downloads/.
The EJB Container in Oracle Application Server provides full support for EJB 2.0 For more information, you can download the EJB 2.0 specifications from http://java.sun.com/products/ejb/downloads/.
The web container in Oracle Application Server provides full support for Servlets 2.3 and JavaServer Pages (JSP) 1.2. For more information, refer to the Sun Microsystems Java Servlet Specification, Version 2.3 which you can download from http://java.sun.com/products/servlet/.
Oracle Application Server provides full support for J2EE Client applications. For more information, refer to the "Application Clients" chapter in the J2EE Platform Specification, Version 1.4 which you can download from http://java.sun.com/j2ee/downloads/.