how to get the super pom basedir in a child module pom? - maven

Question

I want to define a local repository in my maven project.
I've got a super pom and several child modules. My file structure is :
/root
/repository
/child
pom.xml
pom.xml
in my super pom I define :
<repository>
<id>my-local-repo</id>
<url>file://${basedir}/repository</url>
</repository>
The problem is that in my child pom, the repository defined in my super pom refers to /root/child/repository and so, dependencies cannot be found...
Is there a way to define a path always relative to the super pom ?
If not, what's the best way to solve the problem ?

Answer 1

In this case, at first you could try ${project.parent.basedir}.
As it seems it doesn't work, the simple(and native) way is use complete path (/root/...) or try relative path (../) instead of using ${basedir} variable.
But for me, a great solution would be externalize this configuration into a properties file.
You can use properties-maven-plugin ( http://mojo.codehaus.org/properties-maven-plugin/plugin-info.html ).
With this plugin, properties defined on the properties file can be read just like properties defined inside pom.xml.
From the plugin site:
If you have a properties file called teams.properties with this content:
toronto=raptors
miami=heat
Would be the same as declaring the following in your pom.xml:
<properties>
<toronto>raptors</toronto>
<miami>heat</miami>
</properties>

Answer 2

${project.parent.basedir} should do the job.
Or you can set the basedir-path of the root in a property, so it will be inherited. Something like this in the Parent
<properties>
<rootPath>${basedir}</rootPath>
</properties>
And in the Child
<repository>
<id>my-local-repo</id>
<url>file://${rootPath}/repository</url>
</repository>

Answer 3

I solved this many times with groovy plugin. Add a file called "basepath_marker" to your super pom's directory and add the following to your pom. You can access the property like this: ${base-path}. Read this blog post for more details.
Example:
...
<build>
<plugins>
<plugin>
<groupId>org.codehaus.gmaven</groupId>
<artifactId>groovy-maven-plugin</artifactId>
<executions>
<!-- set absolute base path from super pom -->
<execution>
<id>find-basepath</id>
<phase>validate</phase>
<goals>
<goal>execute</goal>
</goals>
<configuration>
<source>
<![CDATA[
import java.io.File;
log.info('## define projects super pom absolute path through basepath_marker')
String p = "basepath_marker";
File f = null;
if( p != null ) {
def _max_child_poms = 0
while( _max_child_poms++ < 5 ) {
f = new File( p );
if( f.exists() ) {
break;
}
p = "../" + p;
}
}
if( f != null ) {
String basePath = f.getCanonicalPath();
basePath = basePath.substring( 0, basePath.lastIndexOf( File.separator ) );
project.properties['base-path'] = basePath.replace( '\\' , '/');
log.info(' - used base path = ' + project.properties['base-path'] );
} else {
log.error( 'Could not find basepath_marker marker file!' );
System.stop( 0 );
}
]]>
</source>
</configuration>
</execution>
</executions>
</plugin>
</plugins>
</build>
...

Answer 4

I try ${basedir}/../ in child pom and it works.
${project.parent.basedir} can not be interpreted.
Also the solution as follow not work, seems ${basedir} is dynamic decided.
define a properties <rootPath> ${basedir} </rootPath> int your parent pom
use ${rootPath} in your child pom

Answer 5

In Parent pom -
Try to use relative path (../) instead of using ${basedir}