The Eclipse git plugin isn't responsible for the build.
But you can customize your Java builder and add a pre-build event which will modify one of your java files with the right version string in it.
- See "Pre-Build events in Eclipse" for adding that pre-build step,
- and use a task like "jgit-buildnumber": a Git "build number" plugin for Maven and Ant based on JGit. That will allow you to get the right version build number string.