Keeping Barbarians at the Gate

My workstation sits at the further end of five workstations aligned adjacently in a row. The walls of the entire floor are painted in white, seemingly dull but immaculate. The dark grey carpet covered across the floor adds sombre to the yet harsh cold August winter.

Looking at the distant window from where I sit,
        I know it’s another bleak day.

I can’t remember if I had seen sunlight two or three days ago. Perhaps four? Maybe there was one yesterday. Seriously, I can’t recall and I can’t be bothered at all.

I’m glued to my screen that I can’t hear the noise around me – because I’m busy keeping the barbarians at the gate.

class  User {

    private TimeInterval accessibleTime;

    private Set<String> accessCodes;



    public User(TimeInterval accessibleTime) {

       this.accessibleTime = accessibleTime;

    }

}

Add null pointer check to parameter and ensure the API validates against incorrect time interval:

    public User(TimeInterval accessibleTime) {

        if (accessibleTime== null) {

            throw new IllegalArgumentException(

                "accessibleTime parameter cannot be null");

        if (accessibleTime.getFromTime() > accessibleTime.getToTime()) {

           throw new IllegalArgumentException("accessibleTime time from [" + acc

essibleTime.getTimeFrom() + "] is later than time to [" + accessibleTime.getTime

To() + "]");

       this.accessibleTime = accessibleTime;

    }

Generate getter and setter methods:

    @YetAnotherNotNullValidation(message = "access codes cannot be null")

    public String getAccessCodes() {

       return accessCodes;

    }



    public String setAccessCodes(Set<String> accessCodes) {

        this.accessCodes = accessCodes;

    }

Hang on, should I expose this setter method even though I have a validation annotation of NotNull hoisted up there? It should be alright I guess, as the validation framework should catch this during runtime. But then again, it requires extra effort to check null values.

    // Someone accidentally wipes out accessCodes somewhere in the code

    user.setAccessCodes(null);



    // and I need to add null check to prevent NPE

    if (user.getAccessCodes() == null) {

        user.setAccessCodes(new HashSet<String>());

    }

Do I want to see this sprinkled everywhere? Perhaps not. It is easy to misuse the setter method and leave accessCode variable in limbo. Better get rid of this, I would rather not have "Midas Touch" effect here.

    doSomething(user.getAccessCodes());

    // to clear out values

    user.getAccessCodes().clear();