How to express "never" with java.util.Date?

Question

I have a class with the fields "deletionDate" and "experiationDate" which could both be undefined, what would mean that the object is whether deleted nor has an expiration date.

My first approach was:

private Date deletionDate = null; // null means not deleted

Having the book "Clean Code" in mind I remember to better use expressive names instead of comments. So my current solutions is:

private static final Date NEVER = null;
private Date deletionDate = NEVER;

I could user a wrapper class around Date, but that would complicate JPA mapping.

What do you think of it? How would you express "never"?

Answer 1

well never is never, not the 1/1/2999.

I would stay with your 1st solution. a Null date means it has not yet happened.

maybe you can wrap it with something like :

boolean isNeverDeleted(){
    return deletionDate == null;
}

Answer 2

You can think about null date as "not available" or "not applicable". If that's the case "NO DATE" is fine for "never".

Don't subtype Date only for a very exquisite style requirement.

A better option is to add semantic to your model object. If your have a Thing object with a deletionDate property you can do:

class Thing
+ deletionDate
+ isNeverDeleted: boolean { return deletionDate == null; }

and it will be practical and documentative, both in the class and in your client code:

if(myThing.isNeverDeleted())