How can I pass the type for the List I want return?

Question

My scenario:

I get a jsonArray, I want to convert this jsonArray to a List of desired type; ie List<Integer> , List<String> etc.

Suppose I have the following method:

public static List jsonArrayToJavaList(JsonArray jsonArray, TYPE TYPE) {
    return new Gson().fromJson(jsonArray, new TypeToken<List<TYPE>>() {}.getType());
}

How do I pass in the TYPE ?

I want to do this because this method could be used by other people and I don't want to duplicate this code for each type of list I want...

I also tried:

public static List jsonArrayToJavaList(JsonArray jsonArray, final Class c) {
    return new Gson().fromJson(jsonArray, new TypeToken<List<c>>() {}.getType());
}

I see the error saying unknown class c.

Answer 1

Java doesn't yet provide an official way to represent generic types . As stated in the javadoc , the TypeToken has been provided in order to give the possibility to represent these types. So, the simple solution would be to use it as a parameter to the jsonArrayToJavaList method. However it will be just an indirection to the call of fromJson.