Question

Is there a standard Java interface with a getName() method that returns a string? I keep finding I have to make my own:

/** objects which know their own names, 
 *  e.g. that are indexed in a Map by their name
 */
interface NamedObject
{
   public String getName()
}

but I’d much rather use a standard one if it’s out there.

---

edit for an example — which I think is somewhat of a red herring to my question, so I specifically do not want answers suggesting alternatives that are specific to the following situation. (I’ve run into the need for a NamedObject interface several times, so I was hoping it was something in a standard library.)

But since you asked for some background context, here it is:

@Override public void stateChanged(ChangeEvent e) {
    Object obj = e.getSource();             
    if (obj instanceof NamedObject)
    {
        String name = ((NamedObject)obj).getName();
        /* do something based on object's name */
    }
}

In my current project, I have a system with three elements: a source, a transmission method, and a receiver. I want to get some information from the source to a receiver, and I control the implementation of both. The transmission method unfortunately is stuck using an object that supports ChangeListener, so all the receiver gets a ChangeEvent with which I can get a source object.

So I have to use implied shared semantics between my source and receiver, i.e. there’s a shared understanding that the source object passed in the ChangeEvent is of class X, where I can pick class X. In this case, all I really care about is the name, from which I can get additional data. I can define my own interface, I was just hoping to be able to use a standard interface since the source and receiver are in different .jar files…

Answer 1

As far as I know, not in the Java SE API.

It is debatable whether a generic NamedObject interface makes sense. Consider for example a Person class and a UnixNamedPipe class. Both could share the same NamedObject interface, but their names actually have vastly different semantics. I can’t see for example a case where it would make sense to have a Collection<NamedObject> with both Persons and UnixNamedPipes.

It would make sense to define such an interface if you have PetCat, PetDog and maybe PetRock classes. But then you will probably have a Pet super class that already defines getName() for all pets. In this case, what the concept of what a “name” is will not change from one pet to another.