In this section, each of the eight types of application XML files, also known as the J2EE Deployment XML Files, are discussed. First, let’s review the four common global application configuration files.

Following are the four common global configuration files for all J2EE application components.

on the job:  All the configuration XML files starting with Orion are also referred to as OC4J-Specific Orion files. The other set of configuration files consist of J2EE-related XML files.

The J2EE application.xml File

The J2EE application.xml file is stored in the j2ee/home/config directory and is

exam watch:  The application.xml file is the main J2EE application deployment descriptor file.

the global application configuration file for all J2EE applications in an OC4J instance. The application.xml file identifies all the Web and EJB applications that are part of a J2EE application. This file points to the location of the jazn-data.xml and the data-sources.xml file. Note that the J2EE application.xml file isn’t the same as the local application.xml files. The latter describe the J2EE EAR files.

The following subsections state the important elements in the application.xml file. The <application> element is the top element in the application.xml file. Within the <application> element, you can use the following elements.

<ejb>pathToEJB.jar</ejb>   The ejb element refers to an EJB JAR.

<alt-dd>path/to/dd</alt-dd>   The alt-dd element represents an optional Uniform Resource Indicator (URI) to the deployment descriptor file for a J2EE module. The deployer will read the deployment descriptor from the default location if you don’t specify the alt-dd element.

<connector>context</connector>   The connector element refers to the URI of a resource adapter archive file.

<context-root>thedir/</context-root>   The context-root descriptor shows the URI of a Web application.

<description>A description.</description>   The description element is a simple description of the application being deployed.

<icon>   The icon element is used to specify the location of application images used in GUI tools.

<java>pathToClient.jar</java>   The java element refers to a Java application client module.

<module>   There are as many module elements as there are separate J2EE modules, and each of them contains EJB, Java, and Web elements.

<web>   The Web element shows the web-uri and the context-root of a Web application module. The <web-uri> element indicates the URI of a Web application file. (A URI is an Internet protocol element consisting of a name or address you can use to refer to a resource. A URL is just an URI that additionally provides a way of accessing and obtaining a representation of the resource.) The URI is relative to the top level of the application package. Here’s the syntax for the <web> element: 

  <web-uri>thePathToThe.war</web-uri>

Here’s a simple application.xml file:

  <application>
    <display-namemyapp j2ee application</display-name>
    <description>
       A sample J2EE application that uses a Container Managed
       Entity Bean and JSPs for a client. 
    </description>
    <module>
      <ejb>myapp-ejb.jar</ejb>
    </module>
    <module>
      <web>
        <web-uri>myapp-web.war</web-uri>
        <context-root>/myapp</context-root>
      </web>
    </module>
  </application>