Calling constructor of a generic type

Question

If I have an abstract class like this:

public abstract class Item
{
    private Integer value;
    public Item()
    {
        value=new Integer(0);
    }
           


        

Answer 1

You can place an abstract method so that the implementing class can determine how to construct the new object.

public abstract T constructT();

and instead of calling

T t = new T()

you would call

T t = constructT();

On your implementing call it would be created as:

new Box() {
    public Integer constructT(){ return new Integer(); }
}