Execute Groovy Online

import groovy.json.JsonBuilder
import groovy.json.JsonSlurper

def discountData = new JsonSlurper().parseText('''
{
 	"SolutionData": {
 		"SolutionType": "New/MACD/ Replace/Reprice",
 		"Activity": "Save/Retrieve",
 		"externalSolId": "4",
 		"externalPsId": "2",
 		"activityType": "pageload",
 		"msPSIId": "",
 		"discAuthLvl": "",
 		"fmrInd": "",
 		"promocd": "",
 		"segment": "",
 		"roleId": "",
 		"strata": "",
 		"billerId": "",
 		"priceplanDetails": [{
 			"PricePlanId": "",
 			"marc": "",
 			"term": "",
 			"RateLetterExpDate": "",
 			"CoterminousIndicator": "",
 			"BundledServiceName": "",
 			"BundledMarcYN": "",
 			"CoterminousExpDate": "",
 			"isbBilled": "",
 			"overrideYN": "",
 			"extendedTermId": "",
 			"pricingSourceId": "",
 			"IcbDiscAppliedByGcsYn": "",
 			"DiscountDetails": {
 				"beid": "",
 				"discountId": "",
 				"discountRefId": "",
 				"offer": {
 					"offercd": "",
 					"country": "",
 					"regioncd": "",
 					"ratePlanId": "",
 					"category": "",
 					"subcategory": ""
 				},
 				"SubGroupDetails": [{
 					"subGroupName": "",
 					"subGroupId": "",
 					"userId": "",
 					"catId": "",
 					"subCatid": "",
 					"sysDfnd": "",
 					"crtdDate": "",
 					"versionNum": "",

 					"activeYN": ""
 				}],
 				"PromoDetails": [{
 					"promocd": "",
 					"desc": "",
 					"regPromoInd": "",
 					"promoRegDataset": "",
 					"startDate": "",
 					"endDate": "",
 					"crtdId": "",
 					"crtdDate": "",
 					"mdfdId": "",
 					"mdfddate": "",
 					"termDatasetName": "",
 					"psocPromoId": ""
 				}]
 			},
 			"SOCList": {
 				"SOCID": "",
 				"SOCVersion": "",
 				"productcd": "",
 				"eRate": "",
 				"Active": "",
 				"effectiveDate": "",
 				"TransactionId": ""
 			},
 			"PriceScenario": [{
 				"PriceScenarioName": ""
 			}]
 		}]
 	}
 }''')

def getDiscountPromoRequest = new JsonBuilder()
def root = getDiscountPromoRequest{
   externalOfferID discountData.SolutionData.externalSolId
   externalPsId discountData.SolutionData.externalPsId
   externalDsgnId 0
   activityType discountData.SolutionData.activityType
   pricePlanDetails discountData.SolutionData.pricePlanDetails
}

println(new JsonBuilder(getDiscountPromoRequest).toPrettyString())