How to filter resource in Maven, replacing with a dependencies artifactId? - maven-2

Question

I'm trying to build a jar that has an xml file as a resource. I'd like to apply a filter to that xml to insert the name of a dependency into the xml. The filtering is working, because I was able to drop in ${project.build.finalName} and get it replaced. I found one hint that the property I'm looking for might be
${project.dependencies[0].artifactId}
but that doesn't seem to work. I'm looking to replace
<fileName>${project.dependencies[0].artifactId}</fileName>
with
<fileName>OtherLibrary</fileName>
Is that possible?
xml, which is in src/main/resources:
<somenode>
<fileName>${project.dependencies[0].artifactId}</fileName>
</somenode>
pom.xml:
<?xml version="1.0" encoding="UTF-8"?>
<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd" xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<modelVersion>4.0.0</modelVersion>
<groupId>com.foo</groupId>
<artifactId>Thing</artifactId>
<version>1.0-SNAPSHOT</version>
<name>Thing</name>
<url>http://maven.apache.org</url>
<build>
<resources>
<resource>
<directory>${basedir}/src/main/resources</directory>
<filtering>true</filtering>
</resource>
</resources>
</build>
<dependencies>
<dependency>
<groupId>com.pts</groupId>
<artifactId>OtherLibrary</artifactId>
<version>1.0-SNAPSHOT</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>3.8.1</version>
<scope>test</scope>
</dependency>
</dependencies>
</project>

Answer 1

Damn, you're right, this property doesn't get replaced during the filtering of resources. That's weird and it sounds like a bug in the Maven Resources Plugin because this property is correctly interpolated during the process-resources phase as I'll demonstrate in the workaround I'm suggesting below (based on the maven-antrun-plugin and the replace task).
First, add the following to your POM:
<plugin>
<artifactId>maven-antrun-plugin</artifactId>
<executions>
<execution>
<phase>process-resources</phase>
<configuration>
<tasks>
<echo>${project.dependencies[0].artifactId}</echo><!-- I'm a test -->
<replace file="${project.build.outputDirectory}/myxmlfile.xml"
token="###" value="${project.dependencies[0].artifactId}"/>
</tasks>
</configuration>
<goals>
<goal>run</goal>
</goals>
</execution>
</executions>
</plugin>
Then, update your XML file into:
<somenode>
<fileName>###</fileName>
</somenode>
With these changes, running mvn process-resources would produce the following result:
$ cat target/classes/myxmlfile.xml
<somenode>
<fileName>OtherLibrary</fileName>
</somenode>
Which proves the property is interpolated (but not set during maven filtering of resources)1. And if you need to filter more than one file, the replace task can take a fileset. Adapt it to suit your needs.
1 Actually, it would be nice to create a new Jira for this bug in the Maven 2.x Resources Plugin. I've created MRESOURCES-118.

Answer 2

The indexed properties will only be available inside plugin configuration due to the way Maven interpolates the POM - so it is available to antrun's replace task, but not the filtering.
However, accessing dependencies by index is not very robust - it is susceptible to changes in the parent. You might instead use the following in pom.xml:
<properties>
<fileName>some-name</fileName>
</properties>
...
<dependency>
<groupId>your.group.id</groupId>
<artifactId>${fileName}</artifactId>
...
</dependency>
You can then continue to filter using the property name:
<somenode>
<fileName>${fileName}</fileName>
</somenode>