Maven build number plugin, how to save the build number in a file?

Question

I've a Java project using Spring Framework and Git and I wanted to display a build number. I found the Build Number Maven plugin. With Git the build number is a Git hash. I dislike that and I thought a date was much more expressive.

I found this excellent blog article explaining how to use build number plugin with a different profile for SVN and Git. Since I just use Git, instead of creating a new profile, I just copied the plugin part in my build tag.

When I run "mvn package" it tells me:

[INFO] --- buildnumber-maven-plugin:1.0:create (default) @ sherd ---
[INFO] Storing buildNumber: 2011-08-04_21-48_stivlo at timestamp: 1312487296631

Which looks ok, but I wonder, where is it stored? "git status" doesn't detect any new file and it seems it's not in target/ too (target/ is in my .gitignore).

Maybe I've to change the configuration to store the build number in a file? How can I use the build number value?

---

Thanks to the hint of Michael-O, I read the chapter about how to filter resource files in Maven Getting Started Guide. I've created a file application.properties in src/main/resources/properties/application.properties with the following contents:

# application properties
application.name=${pom.name}
application.version=${pom.version}
application.build=${buildNumber}

I've added the following XML snippet within my build section:

<resources>
    <resource>
        <directory>src/main/resources/properties</directory>
        <filtering>true</filtering>
    </resource>
</resources>

Now when I call from command line "mvn package", this property file gets saved in target/classes/properties/application.properties, for instance with the following contents:

# application properties
application.name=Sherd Control Panel
application.version=1.0.1-SNAPSHOT
application.build=2011-08-05_05-55_stivlo

Everything works fine from command line, but, sigh, m2eclipse gives Build errors:

05/08/11 6.05.03 CEST: Build errors for obliquid-cp; 
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal
org.codehaus.mojo:buildnumber-maven-plugin:1.0:create (default) on project 
sherd: Cannot get the branch information from the scm repository : 
Exception while executing SCM command.

For some reason m2eclipse tries to connect to my repository, but it can't because it's a Git repository accessed with SSH and a private key. I wonder if I can tell m2eclipse to not connect to Git.

---

After more digging I found about revisionOnScmFailure option, set it to true and now also m2eclipse works. For reference, here is the full configuration of buildnumber maven plugin that I used (it goes in pom.xml in the build / plugins section).

<plugin>
    <groupId>org.codehaus.mojo</groupId>
    <artifactId>buildnumber-maven-plugin</artifactId>
    <version>1.0</version>
    <executions>
        <execution>
            <phase>generate-resources</phase>
            <goals>
                <goal>create</goal>
            </goals>
        </execution>
    </executions>
    <configuration>
        <doCheck>false</doCheck>
        <doUpdate>false</doUpdate>
         <revisionOnScmFailure>true</revisionOnScmFailure>
        <format>{0,date,yyyy-MM-dd_HH-mm}_{1}</format>
        <items>
            <item>timestamp</item>
            <item>${user.name}</item>
        </items>
    </configuration>
</plugin>

Answer 1

Store it in a filtered properties file. See Using maven to output the version number to a text file