Superclass/subclass as Map element problem

[Mark Brading]

Hi all,

I am trying to declare a Map object with an abstract superclass (TableFields_v2) object as follows:-

private Map<Integer, TableFields_v2> elementList;

When I come to create the object element for the Map I want to be able to use a subclass of the superclass for the object; for example:-

this.elementList = new HashMap<Integer, TableFields_v2_Year>();

Where TableFields_v2_Year is a subclass of TableFields_v2

However, Java won't let me do it this way! Can anyone help, or offer a suggestion?


Regards, Mark

[r035198x]

Hi all,

I am trying to declare a Map object with an abstract superclass (TableFields_v2) object as follows:-

private Map<Integer, TableFields_v2> elementList;

When I come to create the object element for the Map I want to be able to use a subclass of the superclass for the object; for example:-

this.elementList = new HashMap<Integer, TableFields_v2_Year>();

Where TableFields_v2_Year is a subclass of TableFields_v2

However, Java won't let me do it this way! Can anyone help, or offer a suggestion?


Regards, Mark

Map<Integer, ? extends MyClass> myMap;

Map where an Integer is mapped to an object whose class extends MyClass.

[Mark Brading]

Map<Integer, ? extends MyClass> myMap;

Map where an Integer is mapped to an object whose class extends MyClass.

r035198x,

Works perfect.

Many thanks for this, Mark