How can i validate json fields from the rest request in my mock service script?

i did the code right now:

i use above script to put on "script log" Pass or Fail information to each json field to be validate

the script works, but i have a problem:

my original switch case have a lot of cases and each request have a lot of validations,

if i do this on this way, the script will be to big and hard to maintain, Ideally I would have a validation file for each case, but i not know how.

my actual onRequest Script:

import com.eviware.soapui.support.XmlHolder
import groovy.json.*

//define request
def request = mockRequest.getRequestContent()

//define "json" which will be the name of my variable
def json = new JsonSlurper().parseText(request)

//define the request identificator for ConsultStatement requests
def identificator = json.address.postalCode

//define file directory
def directory = "c:\\dump"

def timestamp = System.currentTimeMillis()
def requestFile = new File(directory, identificator + ".xml")

switch (identificator){

	case '063842134':
		requestFile.write("PostalCode: " + identificator)
		if (json.address.streetName == "test avenue"){
			requestFile.append("\nPass - streetName: " + json.address.streetName)
		}
		else {
			requestFile.write("\nFail - streetName: " + json.address.streetName + ", expected: test avenue")
		}
		if (json.address.number == "123"){
			requestFile.append("\nPass - number: " + json.address.number)
		}
		else {
			requestFile.append("\nFail - number: " + json.address.number + ", expected: 123")
		}
		// if-else will be repeat for all request fields
		// next case contain same validations...
}

the output file should help testers to identify defects