java List extends abstract

Question

I have a

public abstract class Person{/*..*/}

public class Woman extends Person{/*..*/}
public class Man extends Person{/*..*/}

I'm trying to instantiate a List that could contain either Man or Woman, I tried this :

List<? extends Person> PersonTypes = new List<? extends Person>()

But it can't be instantiated, is there a way to achieve what I want and keeping Person abstract ?

score 2 · Answer 1 · answered Feb 25 '14 at 15:16

2

It should work.

List<Person> PersonTypes = new ArrayList<Person>()

answered Feb 25 '14 at 15:16

RMachnik

score 2 · Accepted Answer · edited Feb 25 '14 at 15:17

2

List is an Interface and thus cannot be instantiated itself, similar to your abstract Person class which cannot be instantiated either.

You should instantiate a class which implements List, such as ArrayList:

List<Person> people = new ArrayList<Person>();

edited Feb 25 '14 at 15:17

Rohit Jain

answered Feb 25 '14 at 15:17

Daniël Knippers

Ok thanks, i should have think about that, what stupid mistake I made. Thx it works now – user3332598 Feb 25 '14 at 16:51

score 0 · Answer 3 · answered Feb 25 '14 at 15:16

0

The List is also an interface and cannot be instantiated. Try this:

List<? extends Person> PersonTypes = new ArrayList<Person>();

answered Feb 25 '14 at 15:16

jgitter

This won't compile. You can't instantiate a wildcard parameterized type. – Rohit Jain Feb 25 '14 at 15:17

3 Answers3