Using GSON to parse array with multiple types

I wish to use GSON to parse the following json:

[
    [
        "hello",
        1,
        [2]
    ],
    [
        "world",
        3,
        [2]
    ]
]

So, that's 1 array, containing 2 arrays. The 2 inner arrays are themselves arrays, comprised of String, int, array types.

I'm unsure how I can using Java classes to model the array which has 3 different types (String, int, array). I start with:

// String json just contains the aforementioned json string.

ArrayList<ArrayList<XXX>> data = new ArrayList<ArrayList<XXX>>();

Type arrayListType = new TypeToken<ArrayList<ArrayList<XXX>>>(){}.getType();

data = gson.fromJson(json, arrayListType);

But what should be where the 'XXX' are? I think it should be an array, but it should be an array with 3 different data types. So how can I use Java to model this?

Can any help? Thank you.