fetch local GIT branch on jenkins build

I'm not familiar with the jgitflow process, and I'll try to read up on that and tailor my answer, but for now I wanted to point you to this really great article on doing maven deployments - Maven Release Plugin: Dead and Buried. The article talks about using an externally set version in their pom file - they embed a 'sane default' property into their codebase.

    <properties>
        <!-- Sane default when no revision property is passed in from the commandline -->
        <revision>0-SNAPSHOT</revision>
    </properties>

They then reference that property in their <build> description

    <build>
        <plugins>
            <plugin>
                <artifactId>maven-scm-plugin</artifactId>
                <version>1.9.4</version>
                <configuration>
                    <tag>${project.artifactId}-${project.version}</tag>
                </configuration>
            </plugin>
        </plugins>
    </build>

When invoking maven, they pass a custom parameter to it from their CI server - mvn deploy scm:tag -Drevision=$BUILD_NUMBER

I'm sure that with the jgitflow plugin, you may be able to have an internal property similar to the above configuration, but use it as a part of your jgitflow version with the branch information passed into your build.

--- Response to feedback ---

If you are just trying to extract the last part of the branch identifier, there are several ways you can do it. If you just want everything after the last /, you could use the basename utility.

$ BRANCH="origin/feature/JIRA-0101"
$ basename $BRANCH
JIRA-0101

You could be more specific with a regular expression that expects the ASDF-1234 style pattern

$ echo $BRANCH | sed -e 's|.*/\([A-Z]*-[0-9]*\)$|\1|g'
JIRA-0101

And if you want to capture the above into a new variable, you can use a subshell, either directly in your call to maven

mvn clean install -Dbranch=$(echo $BRANCH | sed -e 's|.*/\([A-Z]*-[0-9]*\)$|\1|g')

Or storing it in an intermediate variable that you could test to verify is nonzero length

JIRA_ID=$(echo $BRANCH | sed -e 's|.*/\([A-Z]*-[0-9]*\)$|\1|g')
[[ -z "${JIRA_ID}" ]] && echo "Unable to determine JIRA_ID" && exit 1
mvn clean install -Dbranch=${JIRA_ID}

If you need to pass the variable to a different step (if directly using the maven plugin), you will need a plugin similar to the envinject environment injection plugin, described in this answer