Get list of branches within groovy on Jenkins. /** On first run, text field should be set as 'Editable' and branch name e.g. 'master' should be entered manually; then list will be fetched **/

listOfBranches.groovy

import jenkins.model.*

import jenkins.model.Jenkins
import hudson.model.User
import hudson.security.Permission
import hudson.EnvVars

BUILD_JOB_NAME = "APK_TEST"

def jobWorkspace (String jobName) {
    jenkins.model.Jenkins.instance.getJob(jobName).getWorkspace()
}

def showbranches(cmd) {
    def proc = cmd.execute(null, new File(jobWorkspace(BUILD_JOB_NAME).toURI()))
    def sb = new StringBuffer()
    proc.waitForProcessOutput(sb, sb)
    def cod = proc.exitValue()
    if (cod != 0)
        throw new Exception("Error ${cod} when invoking '${cmd}':\n${sb}")
    sb.toString()
}

showbranches("git fetch --all")
showbranches("git remote prune origin")
def re = ~ /->/
List<String> branches = showbranches("git branch -r")
                                .tokenize("\n")
                                .grep({!re.matcher(it).find()})
                                .collect(){it.replace("origin/", "").trim()}
                                .collect()
branches