Sort the JSON Body of HTTP Request alphabetically

I am doing an API call with certain parameters. The body of the Request is something like this:

{
  "billing": {
    "firstname": "John",
    "lastname": "Master",
    "email": "abc.com"
  },
  "address": {
    "firstname": "John",
    "lastname": "Master",
    "email": "abc.com",
    "telephone": "+919999999999"
  },
  "payments": [
    {
      "code": "abcd",
      "amount": 500
    }
  ],
  "refno": "abcd123",
  "successUrl": "https://baseurl/ordercomplete/success",
  "failureUrl": "https://baseurl/ordercomplete/failure",
  "products": [
    {
      "sku": "sampleSKU",
      "price": 500,
      "qty": 1,
      "currency": 356,
      "giftMessage": "",
      "theme": ""
    }
  ],
  "syncOnly": true,
  "deliveryMode": "API"
}

I want to sort the parameters of the request alphabetically. The sorting should be done at outer level and inner level as well. For example, address should come before billing after the sort. Within the internal JSON also I want it to be sorted. For example in the billing struct email should come before lastname.

So the answer that I am looking for is:

{
	"address": {
    "firstname": "John",
    "lastname": "Master",
    "email": "abc.com",
    "telephone": "+919999999999"
  },
  "billing": {
    "firstname": "John",
    "lastname": "Master",
    "email": "abc.com"
  },
  "deliveryMode": "API",
  "failureUrl": "https://baseurl/ordercomplete/failure",
  "payments": [
    {
      "code": "abcd",
      "amount": 500
    }
  ],
  "products": [
    {
      "sku": "sampleSKU",
      "price": 500,
      "qty": 1,
      "currency": 356,
      "giftMessage": "",
      "theme": ""
    }
  ],
  "refno": "abcd123",
  "successUrl": "https://baseurl/ordercomplete/success",
  "syncOnly": true
}

I think I can do this by creating multiple POJO class having all the field and then implement a comparator which will sort it alphabetically. But this way of doing will make it very difficult even if a single field in the parameter of the request body change.

So I was thinking can we do it some better way where we do not have to worry about the field structure.

You could use Jackson ObjectMapper and configure ObjectMapper as

om.configure(SerializationFeature.ORDER_MAP_ENTRIES_BY_KEYS, true);

Hope it was useful.