Deserializing JSON when there are properties with collections

I have successfully used Spring & Jackson as follows,

ResponseEntity<MyClass> result = restTemplate.exchange(
                    MYURL, HttpMethod.POST, entity,
                    MyClass.class);

Here MyClass is a POJO where there is a field mapped with each field in the JSON.

And also I could map the situations where there are many JSON "objects"

ResponseEntity<MyClass[]> responseEntity = restTemplate.getForEntity(MYURL, MyClass[].class);

This parses a simple array of objects and it worked fine.

But now I am in a more complicated situation. I have a JSON like this.

{
    "id": "1998",
    "items": {
        "1": {
            "map": {
                "1": "1.2",
                "2": "2.5",
                "3": "6.1",
                "4": "5.4",
                "5": "9.7",
                "6": "4.23",
                "7": "7.65",
                "8": "1.1",
                "9": "8.5",
                "10": "6.2"
            }
        }
    }
}

In the "items" array you can have another items as "2" or "3". Each of them contains a different "map". I wan't to map these information into an Object.

Obviously the array approach above does not work work since there is a property "id" there.

How can I design a POJO for this? Do I need to write a Custom Deserializer for this?