如何通过JSON值从嵌套的JSON对象列表中获取索引- Groovy

import groovy.json.JsonSlurper

def json = '''
{
  "employees": [
    {
      "firstName": "John",
      "lastName": "Doe"
    },
    {
      "firstName": "Jane",
      "lastName": "Smith"
    }
  ]
}
'''

def slurper = new JsonSlurper()
def data = slurper.parseText(json)

def lastName = data.employees[0].lastName
println lastName

Doe