Injecting current git commit id into Java webapp

I don't know if there are any Ant task for git (I googled a bit without success), anyway Ant can update a properties file with Piotr's option (git rev-parse HEAD) and then in runtime use that properties to get the revision number. This is cleaner and IDE friendly than having Ant generating a .java file.

You can get the last commit SHA with

git rev-parse HEAD

but it's generally a lot more useful to use

git describe

which will give you something that looks like this:

v0.7.0-185-g83e38c7

This works if you have tags - it will tell you how many commits from the last valid tag your current checkout is at plus a partial SHA for that commit, so you can use it to base a checkout off of later. You can use this identifier just like a SHA in most circumstances, but it's much more human readable.

I wrote an Ant task to get the buildnumber using JGit API (without git command line app), see jgit-buildnumber-ant-task. Then you can store this buildnumber inside MANIFEST.MF file and get it from the classpath on runtime.

If it helps for someone else. I know yours is ANT

For MAVEN build, you could probably use git-commit-id-plugin in your pom.xml file

    <plugin>
        <groupId>pl.project13.maven</groupId>
        <artifactId>git-commit-id-plugin</artifactId>
        <version>2.2.0</version>
        <executions>
            <execution>
                <goals>
                    <goal>revision</goal>
                </goals>
            </execution>
        </executions>
        <configuration>
            <dotGitDirectory>${project.basedir}/.git</dotGitDirectory>
            <generateGitPropertiesFile>true</generateGitPropertiesFile>
            <generateGitPropertiesFilename>${project.build.outputDirectory}/git.properties</generateGitPropertiesFilename>
        </configuration>
    </plugin>

Please go through :
1. http://www.baeldung.com/spring-git-information &
2. https://github.com/ktoso/maven-git-commit-id-plugin for more info.