modelling XML dependencies between projects using maven - maven-2

Question

I'm building an application that is composed of two projects: common and theApp.
Now, theApp depends upon common (modelled using a dependency). The tricky thing i'm facing is:
There are XML files in common/src/main/env which will be needed while theApp is running.
To make things more fun, a distribution of run will have this structure:
bin/ - has scripts
lib/ - has the jars created by theApp and common
dependencies/ - has the library jars on which the app depends
config/ - has the xml files from theApp and common
I'm all done, except that I'm still looking for a way to write a maven goal in theApp's POM that can put common's XML files in config/.
Any ideas?
Thanks,
Harshath

Answer 1

You'll need the maven assembly and dependency plugins. Create an assembly descriptor in common/src/main/resources/assemblies/config.xml like this:
<assembly>
<id>config</id>
<formats>
<format>zip</format>
</formats>
<fileSets>
<fileSet>
<directory>${basedir}/src/main/env</directory>
<outputDirectory>/</outputDirectory>
</fileSet>
</fileSets>
<dependencySets>
<dependencySet>
<useProjectArtifact>false</useProjectArtifact>
<useTransitiveDependencies>true</useTransitiveDependencies>
<outputDirectory>config/</outputDirectory>
</dependencySet>
</dependencySets>
</assembly>
Then use it in your pom like:
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<configuration>
<descriptorRefs>
<descriptorRef>config</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<phase>package</phase>
<goals>
<goal>attached</goal>
</goals>
</execution>
</executions>
<dependencies>
<dependency>
<groupId>my.groupid</groupId>
<artifactId>common</artifactId>
<version>my.version</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
This'll create an attached artifact common-config.zip, which you can expand with the maven-dependency-plugin inside theApp's pom.xml, putting the files in theApp's target/config directory (which may not be suitable, depending on how you're creating your final distribution):
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<id>unpack-dependencies</id>
<phase>package</phase>
<goals>
<goal>unpack</goal>
</goals>
<configuration>
<artifactItems>
<artifactItem>
<groupId>my.groupid</groupId>
<artifactId>common</artifactId>
<version>my.version</version>
<type>zip</type>
<overWrite>true</overWrite>
<includes>*</includes>
<outputDirectory>${project.build.directory}/config</outputDirectory>
</artifactItem>
</artifactItems>
</configuration>
</execution>
</executions>
</plugin>
Some of this is documented in http://www.sonatype.com/books/mvnref-book/reference/assemblies.html ...