Question

I have this method, that can return three different response.

At first, it was supposed just only return two, so I make its return type to Boolean

like:

public static boolean isLoteWaitingForImage()

And some business logic came out with that it can has another result, so the method was modified to

public static boolean isLoteWaitingForImage() throws ImageNotPendingException 

If a certain select return a null value, but one row its return true, if its not null i will return false. If no row was acquired from the select I will throw an ImageNotPendingException cause it doesn’t apply for the given filters in the where clause.

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Also thought about doing it in this Way, I have this new Class with the types that are valid to return from the method isLoteWaitingForImage(), with 3 constants properties called:

public class LoteResponse {
    public static int VALID = 1;
    public static int INVALID = 2;
    public static int NO_IMAGE_PENDING = 3;
}

So I will have this new method:

public static int isLoteWaitingForImage() {

    return LoteResponse.VALID;
}

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Having this on table, I have these two questions:

• Any “other” idea about how to accomplish this needing?

• Which method is a better practice?

Answer 1

Yes, that looks like an abuse to me.

It would be reasonable to throw the exception if the method simply shouldn’t be called when no image is pending. Can the client always know that? Does it represent a bug, or something else going badly wrong for them to be calling it in that state? If not, don’t use an exception.

It looks to me like you need an enum.

public enum LoteResponseState
{
    Valid,
    Invalid,
    NoImagePending;
}

public static LoteResponseState getLoteState()
{
    ...
}