Question

I have an immutable class , with the following layout ,

public final class A <T> {
    private ArrayList<T> myList;
    private A(){
        myList = new ArrayList<T>();
    }
    public A<T> addData(T t){
        A newOb = // make a new list and instantiate using overloaded constructor
        T newT = new T(); ***********ERROR HERE*************
        newOb.myList.add(newT);
        return newOb;
    }
    .........
}

The error that I get here is cannot instantiate type T . Now , I think this is related to maybe type erasure in Java.

How can I overcome this ? I want to add a new copy of the argument that is being passed to addData into my list.

Answer 1

In java language generics are implemented by erasure, so it is impossible to instantiate a generic type. Also it is impossible to instiate an array of generic type and so on.

How can I overcome this ? I want to add a new copy of the argument
that is being passed to addData into my list.

You can try to use Cloneable interface as a type bound or add your own similar interface.