jsonbuilder: how to create map of objects

Question

I've been trying to create a map of objects with jsonBuilder for a few hours already with no success. What I want to do is to create such json, so that I can adress my objects like this: someJsonObject.elements.2. Desired JSON looks like this (it's perfectly correct syntax):

{
    "elements": {
        "1": {
            "id": 1,
            "x": 111
        },
        "2": {
            "id": 2,
            "x": 222
        },
        "3": {
            "id": 3,
            "x": 333
        }
    }
}

Best results so far I got with this code:

builder.elements() {
    elementList.each { Element e ->
        element( id : e.id, x : e.x )
        println "dodano"
    }
}

But all I get is only one element printed in my json:

{
    "elements": {
        "element": {
            "id": 3,
            "x": 333
        }
    }
}

If I only could name my objects dynamicly, for instance like this:

builder.elements() {
        elementList.each { Element e ->
            e.id( id : e.id, x : e.x )
            println "dodano"
        }
    }

but it gives me an error: No signature of method: com.webwaver.website.Element.id() is applicable for argument types: (java.util.LinkedHashMap) values: [[id:3, x:748]]

Has anyone got any idea how to get desired json?

EDIT: Thank's for answer. That helps a lot, but since I can't use method call builder.elements() I still have got a problem with creating json, that would look like this:

{
    "data": {
        "lastPageNr": 1,
        "lastLanguageId": 1,
        "lastElementNr": 0,
        "websiteId": "nrpntf"
    },
    "elements": {
        "1": {
            "id": 1,
            "x": 111
        },
        "2": {
            "id": 2,
            "x": 222
        },
        "3": {
            "id": 3,
            "x": 333
        }
    }
}

any ideas?

Answer 1

This gives you the output you want:

import groovy.json.*

def builder = new JsonBuilder()
builder.elements {
  "1" {
    id 1
    x  111
  }
  "2" {
    id 2
    x  222
  }
  "3" {
    id 2
    x  222
  }
}
println builder.toPrettyString()

So what you want for your list based builder is something like:

def elementList = [ [ id: 3, x:748 ], [ id: 4, x:222 ] ]
def builder = new JsonBuilder()
builder.elements {
  elementList.each { e ->
    "$e.id" {
      id e.id
      x  e.x
    }
  }
}
println builder.toPrettyString()

Edit -- after you changed the question:

def builder = new JsonBuilder()
builder {
  data {
    lastPageNr 1
    lastLanguageId 1
    lastElementNr 0
    websiteId 'nrpntf'
  }
  elements {
    elementList.each { e ->
      "$e.id" {
        id e.id
        x  e.x
      }
    }
  }
}
println builder.toPrettyString()