Maven ear Plugin

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External

Internal

Overview

Each Maven module creates just one artifact, and as EARs are aggregations of multiple artifacts, a project that produces an EAR has at least two modules: the module that produces the EAR and the module that produces the actual content (WAR, JAR, etc.).

Playground Example

The following example shows how to build an EAR that contains a library JAR and a WAR. It is a three-module Maven project.

The interesting pom.xml that builds the EAR is found here:


https://github.com/NovaOrdis/playground/blob/master/jee/ear/war-and-lib/ear/pom.xml

Notes

  • The WAR dependency must be explicitly declared of type "war", otherwise the dependency management will attempt to find a JAR and fail.
  • The EAR plugin automatically generates an application.xml:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE application PUBLIC
	"-//Sun Microsystems, Inc.//DTD J2EE Application 1.3//EN"
	"http://java.sun.com/dtd/application_1_3.dtd">
<application>
  <display-name>ear-example</display-name>
  <module>
    <java>ear-embedded-lib-1.jar</java>
  </module>
  <module>
    <web>
      <web-uri>ear-embedded-web-application-1.war</web-uri>
      <context-root>/example</context-root>
    </web>
  </module>
</application>
  • If <jboss> is specified in the plugin's configuration, Maven will also generate a JBoss-specific deployment descriptor. Versions seem to be supported by default up to 5.

Including Libraries within an EAR

Java libraries can be included within an EAR as java modules or as JARs within the EAR's /lib directory.

Java Modules

Specify <includeInApplicationXml>true</includeInApplicationXml>. This will make Maven to generate <java> <module> configuration in application.xml:


<plugin>
  <artifactId>maven-ear-plugin</artifactId>
    <configuration>
      <modules>
        <jarModule>
          <groupId>io.novaordis.playground.jee.ear.war-and-lib</groupId>
          <artifactId>ear-embedded-lib</artifactId>
          <!--
                 If the following flag is not specified, the JAR will be embedded in the EAR's root
                 but no corresponding <java> <module> will be added to application.xml module list.
           -->
          <includeInApplicationXml>true</includeInApplicationXml>
        </jarModule>
        ...
      </modules>
   </configuration>
</plugin>


  • Subject to visibility rules ... see