Re: Generics and subclasses


"EdwardH" <edwardh@N:O:S:P:A:M:edward.dyndns.org> schrieb im Newsbeitrag
news:pmP8f.149348$dP1.507244@xxxxxxxxxxxxxxxxxx
>I have two classes, Manager and Data. I use them as follows...
>
> Class Manager
> {
> private Vector<Data1> dataVector;
>
> add()
> {
> dataVector.add( new Data1(blabla) );
> }
> }
>
>
> What I want to do is use the same Manager class use several Data-typed
> classes, Data1, Data2 and Data3. They all have the same Interface but work
> differently.
>
> Unfortunately Manager doesn't want to work with Interfaces (DataInterface,
> for example) because of the "new".
>
> Does anyone have any suggestions as to how to make Manager more flexible?

I think what you want is this:

Class Manager
{
private Vector<DataInterface> dataVector;

add(){
dataVector.add( new Data1(blabla) );
}

}

class Data1 implements DataInterface{
}

notice: the dataVector accepts objects of type DataInterface. When you
actually add data, you will create a Data1 object (with "new") but it will
be of type DataInterface as well.

You seem to have overlooked that you can use Interface types like this:

DataInterface myData = new Data1();

HTH,
andreas



.

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