Creating Jenkins Folder via web request with Grails / REST

JenkinsService.groovy

import grails.plugins.rest.client.RestBuilder
import grails.transaction.Transactional
import sun.misc.BASE64Encoder

@Transactional
class JenkinsService {
  
    def grailsApplication
    def createJob(String folderName) {
        String url = grailsApplication.config.jenkins.url
        def rest = new RestBuilder(connectTimeout: 10000);
        def base1 = 'createItem?name='
        def base2 = '&mode=com.cloudbees.hudson.plugins.folder.Folder&from=&json=%7B%22name%22%3A%22'
        def base3 = '%22%2C%22mode%22%3A%22com.cloudbees.hudson.plugins.folder.Folder%22%2C%22from%22%3A%22%22%2C%22Submit%22%3A%22OK%22%7D&Submit=OK'
        def jobUrl = "${url}${base1}${folderName}${base2}${folderName}${base3}"

        def resp = rest.post(jobUrl) {
            auth getAuth()
            contentType "application/x-www-form-urlencoded"
        }

        println "Jenkins Job Creation response ${resp.text}"

    }

    private String getAuth() {
        String userName = grailsApplication.config.jenkinsrequest.jenkinsuser.username
        String password = grailsApplication.config.jenkinsrequest.jenkinsuser.password
        String userPassword = userName + ":" + password
        return "Basic " + (new BASE64Encoder().encode(userPassword.getBytes()));
    }
}