Get Object type of class for ArrayList

Question

So, I've tried to get object type of a given class to parse into ArrayList Example:

public class Util{
    public static void makeArray(String tag, Class<?> forClass) {
        ArrayList<?> list = new ArrayList();
    }
}

How can I replace <?> with forClass object type? So back in main method when I call

Util.makeArray("names", String.class);

It would create ArrayList<String> and if I say

Util.makeArray("ages", int.class);

It would resolve it to ArrayList<Integer>

And if it is not even done this way, show how.

bcsb1001 · Accepted Answer · 2018-02-24 18:48:08Z

3

You would use a method type parameter.

public static <T> void makeArray(String tag, Class<T> forClass) {
    ArrayList<T> list = new ArrayList<>();
}

This can be called using Util.<String>makeArray("names", String.class) or you can let the compiler infer T by omitting the <String>.

answered Feb 24, 2018 at 18:48

bcsb1001

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