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 Settingsjpyeron.m2
epositoryorgjmockitjmockit1.11jmockit-1.11.jar my.lib= C:Documents and Settingsjpyeron.m2
epositoryorgjmockitjmockit1.11jmockit-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] ------------------------------------------------------------------------