Easy way to display your apps version number using Maven
Recently I wanted to print our apps version number to the log file. Since I’m using Maven and the Maven Release Plugin to create releases of our app I was looking for an easy way to incorporate the version in the pom.xml into the release and display it.
Fortunately Maven already provides a hook to have the version number written to a jars MANIFEST.MF. I simply added the following snippet to my pom.xml:
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<mainClass>test.App</mainClass>
<addDefaultImplementationEntries>
true
</addDefaultImplementationEntries>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
</build>
The important part is addDefaultImplementationEntries. This instructs Maven to add the following headers to the MANIFEST.MF of your jar:
Now you can use this line of code to access the version number:
where “App” is just any class in your jar.
In defiance of all those Maven haters out there thing are sometimes just that easy with Maven 
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June 5th, 2007 at 4:05 pm
Yes, that is nice functionality provided by Maven.
Something somewhat related that I like to do with web apps is incorporate a build ID into the JSP pages too. The JSP can read it from a properties file that gets updated by Maven dynamically. This is very useful when you have multiple builds on multiple tiers being used by different clients. It’s not really a Maven specific thing but just something I thought of…