Jenkins parse json

jenkinsjob.groovy

//@NonCPS
def parseText(txt){
  return new groovy.json.JsonSlurperClassic().parseText(txt)
}

node ('master') {
  variables = parseText(new File('/tmp/test.json').text)

// this works
  def out = variables.dne.prod.dashboard.stacknameprefix
  print out

// this also works
  print variables.dne.prod.dashboard.stacknameprefix

// and this also works
  def var = 'dne.prod'
  print evaluate('variables.' + var + '.dashboard.stacknameprefix')
  
// or this
  def val = 'dne.prod'
  def map_file = '/tmp/test.json'
  def map = readJSON file: map_file

  def string = 'dne.prod'
  // this is currently broken in jenkins... patching coming
  //def (one, two) = string.tokenize('.')
  def array = string.tokenize('.')
  def val1 = 'dne'
  def val2 = 'prod'
  def map_file = '/tmp/test.json'
  def map = readJSON file: map_file

  print map."${val1}"."${val2}".dashboard.stacknameprefix
  print map."${array[0]}"."${array[1]}".dashboard.stacknameprefix
}