#85 Provide some 'type safety' to receivingapplication interface

[Jens Villadsen]

The following snippet might be useful for other than myself:

public abstract class ATypedApplication<T> implements ReceivingApplication
{
protected abstract Message processMessage(T message);

@Override
public boolean canProcess(Message in)
{
    return true;
}

@SuppressWarnings("unchecked")
@Override
public Message processMessage(Message paramMessage, Map<String, Object> paramMap) throws ReceivingApplicationException, HL7Exception
{
    return processMessage((T) paramMessage);
}

}

[Christian Ohr]

What do you use "T" for?
Do you have separate ReceivingApplication classes by concrete message type?

[Jens Villadsen]

Yep - like the following:

import ca.uhn.hl7v2.model.Message;
import ca.uhn.hl7v2.model.v25.message.ADT_A01;

public class SomeMessageHandler extends ATypedApplication<ADT_A01>{

@Override
protected Message processMessage(ADT_A01 message) {
    // TODO Auto-generated method stub
    return null;
}

}

[Mathieu]

+1 for this feature, I use it too

[Christian Ohr]

Now ReceivingApplication is parameterized regarding the type of the message (<T extends="" Message="">) and processMessage accepts type T. All references to this class have been parameterized as well. Additionally, there's an abstract ClassBasedReceivingApplication class that only accept message of a given class. This can be extended for more specific purposes.