Can I use the path to a Maven dependency as a property?

Question

I have a maven dependency in my pom.xml as such:

<dependency>     <groupId>com.foo</groupId>     <artifactId>Bar</artifactId>     <version>1.2.3</version> </dependency> 

And I would like to use the system path to the binary as a property (so I can pass it to an external process that is kicked off by maven). I can do this in an awkward way:

<properties>     <my.lib>${settings.localRepository}/com/foo/Bar/1.2.3/Bar.jar</my.lib> </properties> 

But I would really like to use a more standard mechanism, such as:

<properties>     <my.lib>${com.foo:Bar:1.2.3}</my.lib> </properties> 

I something like that possible?

Answer 1

Here is a correct implementation, using the maven-dependency-plugin properties goal, which can be used anywhere in a pom:

<?xml version="1.0" encoding="UTF-8"?> <project>     <modelVersion>4.0.0</modelVersion>     <groupId>com.stackoverflow</groupId>     <artifactId>q2359872</artifactId>     <version>2.0-SNAPSHOT</version>     <name>q2359872</name>      <properties>         <!-- Must be listed in the dependencies section otherwise it will be null. -->         <my.lib>${org.jmockit:jmockit:jar}</my.lib>     </properties>     <dependencies>         <dependency>             <groupId>org.jmockit</groupId>             <artifactId>jmockit</artifactId>             <version>1.11</version>         </dependency>     </dependencies>     <build>         <defaultGoal>generate-sources</defaultGoal>         <plugins>             <plugin>                 <groupId>org.apache.maven.plugins</groupId>                 <artifactId>maven-dependency-plugin</artifactId>                 <version>2.3</version>                 <executions>                     <execution>                         <goals>                             <goal>properties</goal>                         </goals>                     </execution>                 </executions>             </plugin>             <!-- Example usage: -->             <plugin>                 <groupId>org.codehaus.mojo</groupId>                 <artifactId>exec-maven-plugin</artifactId>                 <version>1.2</version>                 <executions>                     <execution>                         <goals>                             <goal>exec</goal>                         </goals>                         <phase>generate-sources</phase>                     </execution>                 </executions>                 <configuration>                     <executable>echo</executable>                     <arguments>                         <argument>path to jar=</argument>                         <argument>${org.jmockit:jmockit:jar}</argument>                         <argument>my.lib=</argument>                         <argument>${my.lib}</argument>                     </arguments>                 </configuration>             </plugin>             <!-- end of Example usage -->         </plugins>     </build> </project> 

And the output is...

jpyeron@black /projects/wkspc/tmp/foo $ /cygdrive/c/programs.x86_64/apache-software-foundation/apache-maven-3.1.1/bin/mvn [INFO] Scanning for projects... [INFO] [INFO] ------------------------------------------------------------------------ [INFO] Building q2359872 2.0-SNAPSHOT [INFO] ------------------------------------------------------------------------ [INFO] [INFO] --- maven-dependency-plugin:2.3:properties (default) @ q2359872 --- [INFO] [INFO] --- exec-maven-plugin:1.2:exec (default) @ q2359872 --- path to jar= C:\Documents and Settings\jpyeron\.m2\repository\org\jmockit\jmockit\1.11\jmockit-1.11.jar my.lib= C:\Documents and Settings\jpyeron\.m2\repository\org\jmockit\jmockit\1.11\jmockit-1.11.jar [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESS [INFO] ------------------------------------------------------------------------ [INFO] Total time: 2.032s [INFO] Finished at: Wed Sep 17 12:07:18 EDT 2014 [INFO] Final Memory: 10M/153M [INFO] ------------------------------------------------------------------------ 

Answer 2

Assuming that the com.foo:Bar:jar:1.2.3 artifact is declared as dependency in your POM, the following property returns the path to the jar in the local repository:

${maven.dependency.com.foo.Bar.jar.path} 

Update: Here is a simple POM demonstrating this:

<?xml version="1.0" encoding="UTF-8"?> <project>   <modelVersion>4.0.0</modelVersion>   <groupId>com.stackoverflow</groupId>   <artifactId>q2359872</artifactId>   <version>1.0-SNAPSHOT</version>   <name>q2359872</name>   <properties>     <my.lib>${maven.dependency.junit.junit.jar.path}</my.lib>   </properties>   <dependencies>     <dependency>       <groupId>junit</groupId>       <artifactId>junit</artifactId>       <version>3.8.1</version>       <scope>test</scope>     </dependency>   </dependencies>   <build>     <plugins>       <plugin>         <artifactId>maven-antrun-plugin</artifactId>         <executions>           <execution>             <phase>process-resources</phase>             <configuration>               <tasks>                 <echo>${my.lib}</echo>               </tasks>             </configuration>             <goals>               <goal>run</goal>             </goals>           </execution>         </executions>       </plugin>     </plugins>   </build> </project> 

Running mvn process-resources produces the following output:

 $ mvn process-resources [INFO] Scanning for projects... [INFO] ------------------------------------------------------------------------ [INFO] Building q2359872 [INFO]    task-segment: [process-resources] [INFO] ------------------------------------------------------------------------ [INFO] [resources:resources {execution: default-resources}] [INFO] Using 'UTF-8' encoding to copy filtered resources. [INFO] skip non existing resourceDirectory /home/pascal/Projects/stackoverflow/q2359872/src/main/resources [INFO] [antrun:run {execution: default}] [INFO] Executing tasks      [echo] /home/pascal/.m2/repository/junit/junit/3.8.1/junit-3.8.1.jar [INFO] Executed tasks [INFO] ------------------------------------------------------------------------ [INFO] BUILD SUCCESSFUL [INFO] ------------------------------------------------------------------------ [INFO] Total time: 7 seconds [INFO] Finished at: Tue Mar 02 14:41:32 CET 2010 [INFO] Final Memory: 7M/68M [INFO] ------------------------------------------------------------------------