Using maven to output the version number to a text file

Question

I want to generate a zip file that will update an application with maven. The zip will be hosted on a server and I am using the assembly plugin to generate the zip. However I would like maven to automatically generate a text file that stores the current version number outside the zip. How is this possible?

EDIT: I successfully did it using the maven Assembly Plugin and two descriptors to create two custom assemblies. One has a directory-single goal and it just creates a folder with the updated version.txt based on filtering. Then another one with a single goal actually packages the zip file. This seems to be very inelegant and I guess it will not properly update the maven repo with the whole updated folder. If there is a better way to do this, please let me know.

Answer 1

Sure. Create a text file somewhere in src/main/resources, call it version.txt (or whatever)

File content:

${project.version} 

now in your pom.xml, inside the build element, put this block:

<build>   <resources>     <resource>       <directory>src/main/resources</directory>       <filtering>true</filtering>       <includes>         <include>**/version.txt</include>       </includes>     </resource>     <resource>       <directory>src/main/resources</directory>       <filtering>false</filtering>       <excludes>         <exclude>**/version.txt</exclude>       </excludes>     </resource>     ...   </resources> </build> 

after every build, the file (which you can find in target/classes) will contain the current version.

Now if you want to move the file somewhere else automatically, you are probably going to need to execute an ant task via the maven-antrun-plugin.

Something like this:

  <build>     ...     <plugins>       <plugin>         <artifactId>maven-antrun-plugin</artifactId>          <version>1.4</version>          <executions>           <execution>             <phase>process-resources</phase>             <configuration>                <tasks>                  <copy file="${project.build.outputDirectory}/version.txt"                    toFile="..." overwrite="true" />               </tasks>             </configuration>             <goals>               <goal>run</goal>             </goals>           </execution>         </executions>       </plugin>    </plugins>  </build>