| ------ |
| Creating Skinny WARs |
| ------ |
| Mike Perham |
| Karl-Heinz Marbaise |
| ------ |
| 2014-10-01 |
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| |
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| |
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| |
| Creating Skinny WARs |
| |
| In a typical J2EE environment, a WAR is packaged within an EAR for deployment. The |
| WAR can contain all its dependent JARs in <<<WEB-INF/lib>>> but then the EAR can quickly grow |
| very large if there are multiple WARs, due to the presence of duplicate JARs. Instead |
| the J2EE specification allows WARs to reference external JARs packaged within the EAR |
| via the <<<Class-Path>>> setting in their <<<MANIFEST.MF>>>. |
| |
| The Maven EAR Plugin has direct support for creating skinny wars which simply |
| means to {{{http://maven.apache.org/plugins/maven-ear-plugin/examples/skinny-wars.html}configure the maven-ear-plugin}} |
| accordingly. |
| |
| You need to change the EAR project's <<<pom.xml>>> to package those dependent JARs in the EAR. |
| Notice that we package everything into a <<<lib/>>> directory within the EAR. This is |
| just my own personal preference to distinguish between J2EE modules (which will |
| be packaged in the root of the EAR) and Java libraries (which are packaged in <<<lib/>>>). |
| |
| +-----------------+ |
| <project> |
| ... |
| <build> |
| <plugins> |
| <plugin> |
| <artifactId>maven-ear-plugin</artifactId> |
| <version>2.9.1</version> |
| <configuration> |
| <defaultLibBundleDir>lib/</defaultLibBundleDir> |
| <skinnyWars>true</skinnyWars> |
| </configuration> |
| </plugin> |
| </plugins> |
| </build> |
| ... |
| </project> |
| +-----------------+ |
| |
| Now the painful part. Your EAR project's <<<pom.xml>>> needs to list every dependency that the WAR has. |
| This is because Maven assumes fat WARs and does not include transitive dependencies |
| of WARs within the EAR. |
| |
| +-----------------+ |
| <project> |
| .... |
| <dependencies> |
| <dependency> |
| <groupId>com.acme</groupId> |
| <artifactId>shared-jar</artifactId> |
| <version>1.0.0</version> |
| </dependency> |
| <dependency> |
| <groupId>com.acme</groupId> |
| <artifactId>war1</artifactId> |
| <version>1.0.0</version> |
| <type>war</type> |
| </dependency> |
| <dependency> |
| <groupId>com.acme</groupId> |
| <artifactId>war2</artifactId> |
| <version>1.0.0</version> |
| <type>war</type> |
| </dependency> |
| </dependencies> |
| ... |
| </project> |
| +-----------------+ |
| |
| Your EAR will contain something like this: |
| |
| ----------------- |
| . |
| |-- META-INF |
| | `-- application.xml |
| |-- lib |
| | `-- shared-jar-1.0.0.jar |
| |-- war1-1.0.0.war |
| `-- war2-1.0.0.war |
| ----------------- |
| |
| |
| * Alternatives |
| |
| Our users have submitted alternatives to the above recipe on |
| {{{http://docs.codehaus.org/display/MAVENUSER/Solving+the+Skinny+Wars+problem}the Wiki}}. |