Question

Java design question.

I have an object that needs to maintain sets of say 4 types of widgets: active, inactive, invalid, potential. For each of these types, I have a series of methods that acts on each: say add, get, remove, etc.

My question is, would it be better to have a series of methods like this:

addInactive(Widget)
getInactive()
removeInactive(Widget)
addActive(Widget)
getInactive()
removeInactive(Widget)
addInvalid(Widget)

etc…

OR

Should I have an enum inside this class instead: WidgetStatus and then the consumer would pass in this enum when they need to perform an action. This would result in only 3 public methods instead:

add(Widget, WidgetStatus)
get(WidgetStatus)
remove(Widget, WidgetStatus)

On one hand, I like the first using specialized methods because it not only keeps down the number of parameters needed, but it also forces the consumer’s hand to explicitly call the method they need. However, the latter option seems to keep the API simple and makes adding additional status types in the future a bit easier.

Thoughts?

Answer 1

With the enum you get a cleaner API and much easier maintenance if you want to change the states; there really is no good reason for the first approach.