Is This Use of the “instanceof” Operator Considered Bad Design?

Question

In one of my projects, I have two \"data transfer objects\" RecordType1 and RecordType2 that inherit from an abstract class of RecordType.

I want both RecordType obj

Answer 1

My suggestion:

public RecordType process(RecordType record){
    return record.process();
}

public class RecordType
{
    public RecordType process()
    {
        return null;
    }
}

public class RecordType1 extends RecordType
{
    @Override
    public RecordType process()
    {
        ...
    }
}

public class RecordType2 extends RecordType
{
    @Override
    public RecordType process()
    {
        ...
    }
}

If the code you need to execute is coupled to something the model shouldn't know (like UI) then you will need to use a kind of double dispatch or visitor pattern.

http://en.wikipedia.org/wiki/Double_dispatch