Jenkins groovy script - adds parameters to a job

addParametersToJob.groovy

def jobName = 'MyJob'
def paramNamesAndValues = 'param1=value1&param2=value2&param3=value3'
def j = Jenkins.getInstance()
def job = j.getItem(jobName)
def new_param = []
def params 

def getKeyValueMapFromData(data){
    def result = data.split('&').inject([:]) {
        map, token ->
            println("map: ${map}, token: ${token}")
            token.split('=').with {
                map[it[0]] = it[1]
            }
            map
    }
    return result
}

def paramValue = getKeyValueMapFromData(paramNamesAndValues)
println("INFO: Data map: ${paramValue}")

def prop = job.getProperty(ParametersDefinitionProperty.class)
        if(prop != null) {
          println("--- Parameters for " + job.name + " ---")
          params = prop.getParameterDefinitions()
          
            try {
                paramValue.each{ key, value ->
              
                  new_param.add(new StringParameterDefinition(key, value))
               }  
            }
           
            catch(Exception e) {
              println(e)
              println(param.name)
            }
          
        }
          
new_param.each{ p ->
  println 'new param: '+ p +', name=' +  p.name + ', value=' + p.getDefaultParameterValue()
}


params.addAll(new_param)